There are some sites where you can earn bitcoins from visiting some websites, reading some captchas, answering some polls, etc.
But it is very very very slow !
Yup. Not sure if this wiki is kept updated, but here is a short list:
https://en.bitcoin.it/wiki/Trade#Free_Samples_and_OffersAlso, there is a thread here in the newbies section listing similar types of sites.