Yes, I've read up on this. I have the "old" white 24" iMac. I bought the last one they had, after the new aluminum iMac was announced. The maximum RAM supported is listed at 3GB but this requires un-matched RAM sticks and you pay about a 6% to 8% speed penalty for this because the chipset can't do dual channel reads. (But you gain back more performance due to the increased amount of RAM) They say you can put two 2GB parts in but the iMac will only see 3.3GB. With the price of RAM now lower I may just not care that I'm "wasting" 700MB and install two matched 2GB parts. If I can gain a 6% speedup and also get 0.3GB more RAM it may be worth spending the extra $80 or so. Question: Has anyone tried this?