Get some money back when you shop online by clicking through to retailers on cashback websites. Unfortunately, the small catch is that you can only request payouts once you have a certain amount in your account, which means you need to spend enough to get it. There is also a problem in that each website doesn't support all retailers, so you sometimes have to "shop around" the cashback sites for the best deal - of course meaning you earn a bit less in each, meaning more time until you get money.
However, it's a worthwhile thing to do if you shop online regularly. Here are the ones I use most regularly.
MutualPoints.com
What you do: Shop online and get cashback, usually ranging from 1-5%. You can also sign up to receive up to 3 emails per day - typically, you get 5 points every time you click a link in the emails, or you can earn extra points by registering on websites, downloading software, etc. It might be a good idea to make a new email account for "spam", BUT in order for cashback to work, you have to use the same email address with the retailer as the one you have registered with MutualPoints.
What you get: 3000 points gives you £20. You also get 50 points when you sign up
Minimum payout: 3000 points (£20)
Website: MutualPoints.com
My Shopping Rewards
What you do: Shop online and get cashback.
What you get: £3.50 when you sign up, and money when you buy online or sign up with affiliates, enter competitions etc.
Minimum payout: £20
Website: MyShoppingRewards.com
TrolleyCASH
What you do: Shop online and get cashback.
What you get: £3 when you sign up, and money when you buy online.
Minimum payout: £10
Website: TrolleyCash.co.uk
eCashback
What you do: Shop online and get cashback, plus there are a handful of sign-ups and whatnot.
What you get: Cashback, pure and simple, with a £2.50 bonus when you sign up. It's not an amazing site, but they have the best deal for Amazon.co.uk.
Minimum payout: £20
Website: eCashback.co.uk
Pigsback
What you do: Shop online, complete offers, enter competitions and all sorts.
What you get: 100 PiggyPoints on registration, cashback on all sorts of things. I've never actually used it, although I am a member and it seems quite popular. However, even if you don't want to use it, do sign up because 100 PiggyPoints can be redeemed for a £1 donation to charity.
Minimum payout: 100 PiggyPoints, there are a whole load of rewards available.
Website: PigsBack.com