user238: When creating a bitcoin transaction, you have to choose which coins to use in them. The standard client does this in a way to avoid unconfirmed inputs and minimize the number of inputs and amount of change involved. Since not all coins are created equal, I may have other preferences (like spend unconfirmed coins first to get rid of them, or not cross inputs between different trading partners). Is there any way I can have more control over the process?

user78: Check out Armory, a new client that

uses an algorithm for coin selection which can be optimized for
  anonymity or minimal transaction fees.


user441: Currently this is not possible with the standard client, other than making separate wallets. There is a patch for coin selection on github, which was very promising. So this feature may make it into a future version.

user5292: Old question, so answers are outdated. Anyone reading this now: bitcoin-qt has coin control features that let you choose whichever txin you want to use.

238: <p>When creating a bitcoin transaction, you have to choose which coins to use in them. The standard client does this <a href="https://bitcoin.stackexchange.com/questions/1077/how-does-the-bitcoin-client-determine-which-coins-transactions-wallet-stored-va">in a way</a> to avoid unconfirmed inputs and minimize the number of inputs and amount of change involved. Since <a href="https://bitcoin.stackexchange.com/questions/2496/are-bitcoins-inherently-fungible">not all coins are created equal</a>, I may have other preferences (like spend unconfirmed coins first to get rid of them, or not cross inputs between different trading partners). Is there any way I can have more control over the process?</p>
 78: <p>Check out <a href="https://bitcointalk.org/index.php?topic=56424.0" rel="nofollow">Armory</a>, a new client that</p>

<blockquote>
  <p>uses an algorithm for coin selection which can be optimized for
  anonymity or minimal transaction fees.</p>
</blockquote>
 441: <p>Currently this is not possible with the standard client, other than making separate wallets. There is <a href="https://github.com/bitcoin/bitcoin/pull/415" rel="nofollow">a patch for coin selection on github</a>, which was very promising. So this feature may make it into a future version.</p>
 5292: <p>Old question, so answers are outdated. Anyone reading this now: bitcoin-qt has coin control features that let you choose whichever txin you want to use.</p>
