Bitcoin Faucet
This service sends you SMS messages (no more
than 2 per month) advertising bitcoin related
services, and, in turn, gives you free bitcoin.
FreeCoins
This service pays you a small amount of bitcoin
for answering a captcha check.
LegendaryFaucet
This service pays you a small amount of bitcoin
for answering a captcha check. (Almost idential
to the service above.)
BitSprinkle
Send this bot a message on Twitter with your
bitcoin address, and it'll send you some bitcoin :)
VNBitcoin
This service sends you .0005 BTC after you've
verified an email address with them. They won't
use your email for anything other than
verification, so don't worry about spam! This is
currently one of the best free bitcoin sites out
there.