There is the hacker news spreadsheet: http://spreadsheets.google.com/ccc?key=0AlD_6iEb8Ed9dGs3clVJ...
oDesk has a reasonable number of qualified people
Guru/Rentacoder seem saturated with low bidding "fail 3 times before you get a success" types.
Additionally, the Basecamp people have a site with samples (but the name escapes me).