I recently installed Gentoo Linux (amd64) as a guest on my Mac (OS 10.6 Snow Leopard) using VMWare Fusion. I thought I’d post the kernel config that I am using, since I didn’t find any out there that I trusted. If you can use this as a starting point, then it should save you some time and trouble. It’s a pretty minimal configuration–I think I removed all the extra drivers and stuff. You could lean it out a little more by removing the audio and a few other extras that I thought I might use. Let me know if you have any trouble with it.
So far I am very pleased with its performance. My only disappointment is that VMWare doesn’t support Linux graphics hardware acceleration.