eBay and Craigslist finds

http://sheldonbrown.com/fixed-conversion.html
read up on the net first before you go wasting money

Thanks for responding guys. I am totally new to this.

Yep, the size was part of the appeal, I'm 5'7''. The seller says the frame is 19'' which would be the sort of thing I am after. When I try friend's bikes I find 20'' is the max for me, and it seems like most of the stuff being sold is 20'' and above. (then again I am new to the fixie thing).

I was going to have prof's replace the BB for me anyway,they'll be able to remove the old parts right?

OK, so hub spacing is a real concern, I'd hate to be limited in my choice of wheels. What width should I ideally have?