If you're based in the UK, Trials4Us will pay you to donate blood or take part in clinical trials. I know in America they pay people for donating blood but they don't usually pay you over here, so was quite pleased to find out about this. They'll pay you up to £60 plus expenses to donate blood, and taking part in their clinical studies can earn you a lot more than that (well over £1,000 in some cases). They also pay up to £350 if you refer somebody to them who then takes part in a trial (as long as they mention you referred them when they go).

I know some people can be a bit worries about clinical trials but they're actually very safe. Drugs don't reach this stage until they've been extensively tested by other means and in any case, it's not always drug trials. And £60 for a bit of your blood doesn't sound bad at all!