user78: A friend just asked me "where are the 11 BTC I bought from you half a year ago? ... I don't remember where I put them." He formatted his computer a few months ago, and the money is probably lost (all of your BTCs just got 5.2E-7 more valuable).
I'd like to recommend an easy to use wallet with the following requirements:

You only have to remember a password/passphrase to access all your BTC. Bonus: transaction history as well.
It's super secure. I mean, I'd like 2-factor authentication, and keys should not be stored on the server (maybe only half a key). Let's assume the client computer is Trojan infected as well.
No ID/bloodwork/whatever is needed to use it (I don't know what Mt. Gox requires of "verified" users nowadays).
It is developed by a relatively trusted company/people. Trust is subjective, but still you can provide concrete evidence of why company X is "more trusted by the community" than company Y. 
I'd prefer a no-install browser based wallet, but not if it conflicts with any of the above requirements. 

Are there wallets that comply with most/all of these requirements?

user-1: I think My wallet meets most of these requirements.
1) Sign up only requires a password
2) You can opt to have the keys saved on the server in encrypted format in which case all your friend needs to do is remember a password. Two factor authentication is supported using yubikey or email.
3) Or you can follow the paper wallet tutorial in which case no keys will be stored on the server, but your friend will additionally need to keep the paper wallet part safe.
4) Registered UK Company, my name is Ben Reeves i've been around for a fair while on the bitcoin forums as piuk. Both the server side and client side code is open source.
5) Browser based, works on mobile devices including iPhone, iPad and android.

user323: 
Take a password.
Hash it with SHA.
Use the hash as a private address.
Generate your public address from that private address.

Guess this would be the easiest algorithm for having a deterministic wallet. One could easily make a web service or a program to generate those addresses, but people generally don't trust third party services like this.
EDIT:
StrongCoin allows one to generate a private key from any sentence, and given that they encrypt the private key before your browser sends it out, one can trust them not to know it. Then, you can decrypt the private key (as far as I know, also on your machine), and import it wherever one needs (provided you don't want to keep your coins online). It is a small workaround, but seems to fulfil your friends' needs.

78: <p>A friend just asked me "where are the 11 BTC I bought from you half a year ago? ... I don't remember where I put them." He formatted his computer a few months ago, and the money is probably lost (all of your BTCs just got 5.2E-7 more valuable).</p>

<p>I'd like to recommend an easy to use wallet with the following requirements:</p>

<ul>
<li>You only have to remember a password/passphrase to access all your BTC. Bonus: transaction history as well.</li>
<li>It's super secure. I mean, I'd like 2-factor authentication, and keys should not be stored on the server (maybe only half a key). Let's assume the client computer is Trojan infected as well.</li>
<li>No ID/bloodwork/whatever is needed to use it (I don't know what Mt. Gox requires of "verified" users nowadays).</li>
<li>It is developed by a relatively trusted company/people. Trust is subjective, but still you can provide concrete evidence of why company X is "more trusted by the community" than company Y. </li>
<li>I'd prefer a no-install browser based wallet, but not if it conflicts with any of the above requirements. </li>
</ul>

<p>Are there wallets that comply with most/all of these requirements?</p>
 -1: <p>I think <a href="https://blockchain.info/wallet" rel="nofollow">My wallet</a> meets most of these requirements.</p>

<p>1) Sign up only requires a password</p>

<p>2) You can opt to have the keys saved on the server in encrypted format in which case all your friend needs to do is remember a password. Two factor authentication is supported using yubikey or email.</p>

<p>3) Or you can follow the <a href="https://blockchain.info/wallet/paper-tutorial" rel="nofollow">paper wallet tutorial</a> in which case no keys will be stored on the server, but your friend will additionally need to keep the paper wallet part safe.</p>

<p>4) <a href="https://blockchain.info/about" rel="nofollow">Registered UK Company</a>, my name is Ben Reeves i've been around for a fair while on the <a href="https://bitcointalk.org/index.php?action=profile;u=17928" rel="nofollow">bitcoin forums</a> as piuk. Both the server side and client side code is <a href="https://github.com/zootreeves/blockchain.info" rel="nofollow">open source</a>.</p>

<p>5) Browser based, works on mobile devices including iPhone, iPad and android.</p>
 323: <ol>
<li>Take a password.</li>
<li>Hash it with SHA.</li>
<li>Use the hash as a private address.</li>
<li>Generate your public address from that private address.</li>
</ol>

<p>Guess this would be the easiest algorithm for having a deterministic wallet. One could easily make a web service or a program to generate those addresses, but people generally don't trust third party services like this.</p>

<p>EDIT:
<a href="https://strongcoin.com" rel="nofollow">StrongCoin</a> allows one to generate a private key from any sentence, and given that they encrypt the private key before your browser sends it out, one can trust them not to know it. Then, you can decrypt the private key (as far as I know, also on your machine), and import it wherever one needs (provided you don't want to keep your coins online). It is a small workaround, but seems to fulfil your friends' needs.</p>
