Apologies if you don't like this kind of thing but I thought I would share the following site with you:
http://www.valuedopinions.co.uk/ If you sign up and fill in a few introductory bits and pieces, they will send you - on a fairly frequent basis - online market research surveys to fill in on a variety of topics. Some will only take 5 minutes but others take longer but you get rewarded somewhere between 50p and a couple of pounds for each survey that you complete depending on how long it lasts and when your account balance reaches £5, you can choose how to take you reward. There's a variety of high street vouchers to choose from or you can get amazon vouchers or donate to charity. In the last year, I've made about £30 out of it which is always nice as it's not really that strenuous. Normally I would be incredibly suspicious of something like this but I actually used to work there (and spent one summer stuffing envelopes with Tescos vouchers so I know they exist!) and I've just used £10 worth of amazon vouchers to buy part of my mum's christmas present :D
Like I said, aplogies if anyone doesn't want to read this but I thought some people may appreciate it because it's a pretty easy way to make money.
There are various international sites as well for those of my LJ who are not UK based too I think - the corporate site is www.researchnow.co.uk which says where they have panels. Plus I researched most of the 'fun facts' for the countries :D