Ask YC: Angel investing, where to start?

I've been thinking a lot about angel investing the last few years, and PG's article about it recently rekindled that interest.

But where to start? I'd like to invest with a group of like-minded folks, rather than just on my own, and I'd also like to invest in startups that appeal to me on a personal level (the people, product, or vision). But how to find out who is taking on angel investment and get involved in the process? Any tips, suggestions or stories?