JGC, personally I'd love it if you blogged/wrote somewhere about being/becoming an independent consultant, especially in a righteous/sexy domain like anti-spam/text learning. :)
1. I had no other choice. After years of working for people I just needed a break.
2. It's harder than it looks... my income is totally variable.
3. It's the best thing I ever did. I get to choose what I work on (to a certain extent).
I'm actually thinking of going back full time, but that's only because a start up is enticing me with an interesting combination of good team, interesting problem, and stock.