user1379: I would like to use a USB with a Linux distro, ideally with Electrum. The advantage of this is that the USB does not need to contain any information, just entering the seed would be enough, which provides extra security in my opinion.
Is there a distribution which does this? or there an instruction on how to do this?

user6388: You can make the standard client portable if you use the "-datadir" flag.
Assuming that the application "bitcoin" is accessible from your working directory and that you want to store information in a directory named "data", the script you want looks like this:

#!/bin/sh
bitcoin -datadir=./data

Source: https://bitcointalk.org/?topic=809.0;wap2

user12845: BTCVault (http://dswd.github.io/btcvault/). The client is a little old but the concept works great.

user21640: After writing this message, I realize this thread is about a USB based distribution.
Yet I'm posting about a CD based solution in case it serves the ones who are still searching and deciding...
Here's how I did my setup to be able to exchange bitcoin and litecoin.
I don't want to use two computers for separate offline-and-watchOnly clients.
After searching and reading, I decided to use:

Electrum and Electrum-LTC from a CD-booted operative system,
rigorously offline (I unplug the ethernet cable from the PC so I
still have wifi for my phone), with a portable wallet on a pendrive
and a watch-only Electrum client in Windows (this can be
fully portable so I plug the pendrive just when I need to use the client
and nothing strictly related stays permanently on the PC which is often online)

HOW?
I grabbed the latest Electrum (1.9.8) and Electrum-LTC (1.9.8.6) clients from electrum.org (the Linux versions come with executable binaries, too) and I added them to the current slax distribution (with the necessary modules but not the electrum one, and the startup command launches from inside the electrum folder) and made a bootable CD of it (although it works offline, it's good to know that it cannot be modified like a pendrive-resident environment).
IS THAT SAFE?
As long as the offline part stays offline and as long as slax and Electrum do not contain malicious software which might store my seed phrase somewhere in my hardware, that's pretty safe... apart of course the Electrum servers considerations etc. etc. etc..
If I come to get very rich (but I doubt LOL), I'll start using the Tor network (I already have the connection setup in Windows). (*****)
I saw that another slax based solution was out, I had tried BTCVault, but

the Electrum client is a little old
because of that, I didn't spend more than a couple of hours on it but
I couldn't have Electrum create a new wallet on the pendrive (and in
volatile storage either) through the GUI and the right-mouse-button
contextual menu item "create new wallet here", sure I'm missing
something; I could have it create a new Multibit wallet but that's
not my choice for now.

I have tried two more live CDs, Tails 1.2.2 and Ubuntu 14.10, but the boot time is much greater than with slax, and anyway I need the online watch-only part to run on Windows, and in the offline part of the process I wouldn't use the extra features that Tails and Ubuntu might (or not) offer over slax.
(*****) The only advantage of Tails which is evident to me even for offline use: Tails wipes the memory before shutting down... I don't know how much time I should wait after shutting down slax, before switching on the PC again, no idea.
I hope this helps some other crypto currencies newbies!
With the first "crypto-bucks" I will hopefully earn (I'm offering online lessons, trumpet, rhythm, musical theory :D ), I think I shall have to donate to the Electrum and slax developers, and I promise I'll try to avoid dust transactions and will not be stingy with tx fees.

user110304: I realize this is an old thread.  Since it is showing in google search, it might be worth to reply still.
Check out EROAS.

EROAS stands for "Electrum Running On A Stick". It runs Electrum wallet, the best open source bitcoin wallet, on cheap USB drives, with cold-wallet level security and warm-wallet like convenience. It is meant to operate like a saving account for infrequent transactions (perhaps <1 transaction per day). Its strong security level makes it suitable to protect assets over millions of dollars.


user3211: I have considered building a electrum usb-distro but the problem is it would be hard to keep it updated after each new release. However if there is enough interest I might do so. 
Your best bet is to simply take a debian live-usb and install Electrum on it; you can follow the instructions for linux on the electrum site.
If you have any specific Electrum questions you are always welcome to join #electrum on freenode and ask your questions there. 

1379: <p>I would like to use a USB with a Linux distro, ideally with Electrum. The advantage of this is that the USB does not need to contain any information, just entering the seed would be enough, which provides extra security in my opinion.</p>

<p>Is there a distribution which does this? or there an instruction on how to do this?</p>
 6388: <p>You can make the standard client portable if you use the "-datadir" flag.</p>

<p>Assuming that the application "bitcoin" is accessible from your working directory and that you want to store information in a directory named "data", the script you want looks like this:</p>

<pre>
#!/bin/sh
bitcoin -datadir=./data
</pre>

<p>Source: <a href="https://bitcointalk.org/?topic=809.0;wap2" rel="nofollow">https://bitcointalk.org/?topic=809.0;wap2</a></p>
 12845: <p>BTCVault (<a href="http://dswd.github.io/btcvault/" rel="nofollow">http://dswd.github.io/btcvault/</a>). The client is a little old but the concept works great.</p>
 21640: <p>After writing this message, I realize this thread is about a USB based distribution.
Yet I'm posting about a CD based solution in case it serves the ones who are still searching and deciding...</p>

<p>Here's how I did my setup to be able to exchange bitcoin and litecoin.</p>

<p>I don't want to use two computers for separate offline-and-watchOnly clients.</p>

<p>After searching and reading, I decided to use:</p>

<ul>
<li><p>Electrum and Electrum-LTC from a CD-booted operative system,
rigorously <strong>offline</strong> (I unplug the ethernet cable from the PC so I
still have wifi for my phone), with a portable wallet on a pendrive</p></li>
<li><p>and a watch-only Electrum client in Windows (this can be
fully portable so I plug the pendrive just when I need to use the client
and nothing strictly related stays permanently on the PC which is often online)</p></li>
</ul>

<p><strong>HOW?</strong></p>

<p>I grabbed the latest Electrum (1.9.8) and Electrum-LTC (1.9.8.6) clients from electrum.org (the Linux versions come with executable binaries, too) and I added them to the current slax distribution (with the necessary modules but <em>not</em> the electrum one, and the startup command launches from inside the electrum folder) and made a bootable CD of it (although it works offline, it's good to know that it cannot be modified like a pendrive-resident environment).</p>

<p><strong>IS THAT SAFE?</strong></p>

<p>As long as the offline part stays offline and as long as slax and Electrum do not contain malicious software which might store my seed phrase somewhere in my hardware, that's pretty safe... apart of course the Electrum servers considerations etc. etc. etc..
If I come to get very rich (but I doubt LOL), I'll start using the Tor network (I already have the connection setup in Windows). (*****)</p>

<p>I saw that another slax based solution was out, I had tried BTCVault, but</p>

<ul>
<li><p>the Electrum client is a little old</p></li>
<li><p>because of that, I didn't spend more than a couple of hours on it but
I couldn't have Electrum create a new wallet on the pendrive (and in
volatile storage either) through the GUI and the right-mouse-button
contextual menu item "create new wallet here", sure I'm missing
something; I could have it create a new Multibit wallet but that's
not my choice for now.</p></li>
</ul>

<p>I have tried two more live CDs, Tails 1.2.2 and Ubuntu 14.10, but the boot time is much greater than with slax, and anyway I need the online watch-only part to run on Windows, and in the offline part of the process I wouldn't use the extra features that Tails and Ubuntu might (or not) offer over slax.</p>

<p>(*****) The only advantage of Tails which is evident to me even for offline use: Tails <em>wipes the memory</em> before shutting down... I don't know how much time I should wait after shutting down slax, before switching on the PC again, no idea.</p>

<p><strong>I hope this helps some other crypto currencies newbies!</strong></p>

<p><strong>With the first "crypto-bucks" I will hopefully earn (I'm offering online lessons, trumpet, rhythm, musical theory :D ), I think I shall have to donate to the Electrum and slax developers, and I promise I'll try to avoid dust transactions and will not be stingy with tx fees.</strong></p>
 110304: <p>I realize this is an old thread.  Since it is showing in google search, it might be worth to reply still.</p>
<p>Check out <a href="https://github.com/monkey-jsun/eroas" rel="nofollow noreferrer">EROAS</a>.</p>
<blockquote>
<p>EROAS stands for &quot;Electrum Running On A Stick&quot;. It runs Electrum wallet, the best open source bitcoin wallet, on cheap USB drives, with cold-wallet level security and warm-wallet like convenience. It is meant to operate like a saving account for infrequent transactions (perhaps &lt;1 transaction per day). Its strong security level makes it suitable to protect assets over millions of dollars.</p>
</blockquote>
 3211: <p>I have considered building a electrum usb-distro but the problem is it would be hard to keep it updated after each new release. However if there is enough interest I might do so. </p>

<p>Your best bet is to simply take a debian live-usb and install Electrum on it; you can follow the instructions for linux on the electrum site.</p>

<p>If you have any specific Electrum questions you are always welcome to join #electrum on freenode and ask your questions there. </p>
