Check this site out, it's a survey group called YouGov (heard of em?), they send you surveys and each one you complete they pay you either 50p or Ł1. Once you get to Ł50 they send you a cheque through the post. This isn't a scam, and whose results have been referenced in national newspapers on all sorts of topics, politics, Iraq, sport you name it.
The surveys only take a couple of minutes each. Link:-
Could be useful if when you need a few bob...