There are several sites where you can get a small amount of bitcoins (more like fractions of bitcoins, really) for entering a captcha or clicking an ad. Find out more in this topic.

It's by no means 'worth the pay' (i.e. it's quite not enough to make a living with it ) but just consider it a test to get yourself started with some bitcoin pennies. Some are stupid and require you to waste lots of time, some are plain and simple, just enter a captcha or click an ad or something, and you'll receive coins within a few hours.