I have a partially working implementation of idle detection that willat the cost of mining performanceprevent the miner from using too much system resources when the machine is in use. This is not fully working yet, but Ill get there.
Great news!
I wonder if it would be possible for the user to input the idle detection time? Sometimes a minute would be all that it needs to crank back up to 100%. Other times, when I'm seriously working on the machine I might want to kick it back to 10 or 15 minutes idle wait so as not to interfere. Of course right now, I have the option of turning it off completely although still with the excitement of not receiving my first bitcoin yet, I'm tolerating a very sluggish screen.

I'm on a MacPro 8-core on OSX 10.6.7 with an ATI 5870 with an Artic Cooler. I must say it is rather disappointing to see only 156 Mhash/sec when others on the PC are reporting easily more than double (and someone claimed 421). It would be nice if there were some options to optimize performance on the Mac to squeeze a 'bit' more performance (sorry).
EDIT I just installed the latest version DiabloMiner-GPU-Bitcoin-miner-20110618.zip and at first I thought I saw an increase in speed. I saw number over 205,000 that really excited me. Then, slowly it started dropping down. Now it seems to be running about the same rate as before. I see 156,000/160,000 khash/sec
btw, why the fraction? What do the two numbers mean?
Are there any ways to set the vector worksize to 128? Might this not provide some advantage?