I've been looking into Gentoo -- haven't mucked with it yet, but it's interesting.
The thing that makes it really interesting to me is that it does with source what Debian does with a binary... it's apt-get and an automated compiler all thrown together. Which means (I think) that you don't have to maintain separate software repostories for different processors... you just grab the source and compile it for your pentium or for your AMD 64 processor, or for your powerpc, and you're good to go.
The problems I see are that apparently it's a pain the ass to install (there are, I'm told, TEN STAGES of installation) and I have no idea how easy the "grab and compile" tool is for non-programmers. From what I read it's similar to apt-get *after* you configure it, but I don't know what's involved in the configuration part. (I guess that's part of the installation process?)
Anyone have any experience with this distro?