Currently I am using guiminer:
http://guiminer.org/I found that it really takes forever to get any bitcoins at all from mining them yourself with only one halfway decent GPU. Instead I have set up an account with slush's pool (
https://mining.bitcoin.cz/ ) and inputted the name of my "worker" and it's password into guiminer. The GPU I am using is a Saphire Radeon 6850HD and I am averaging about 140Mhash/sec (this is not the full capability of the GPU, I have it limited to keep the heat down).
All of this yeilds me about 0.01 BTC every 2 days or so. Yeah, I'm probably paying more in electricity to run it. I am currently working on modifying the chrome bot posted here:
https://bitcointalk.org/index.php?topic=67591.0 so it can do short trades while I am at work. This way I may be able to make more money trading, while I also mine.