Question: When creating a bitcoin transaction, you have to choose which coins to use in them. The standard client does this [in a way](https://bitcoin.stackexchange.com/questions/1077/how-does-the-bitcoin-client-determine-which-coins-transactions-wallet-stored-va) to avoid unconfirmed inputs and minimize the number of inputs and amount of change involved. Since [not all coins are created equal](https://bitcoin.stackexchange.com/questions/2496/are-bitcoins-inherently-fungible), 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?

Answer: 
Old question, so answers are outdated.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.
Check out [Armory](https://bitcointalk.org/index.php?topic=56424.0), a new client that

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