selling your unwanted electricals

http://www.cash4gagdets.co.uk/ hair straighteners and laptops etc
http://www.weeebuy.co.uk/; as above

money making holidays

If you can solve the puzzles set by treasure trails,you will be entered into a draw.

tradeyourgames.co.uk

http://www.tradeyourgames.co.uk/
you could  sell your video games,consoles and blu-rays to them for cash

Turning your home into holiday accomodation

http://www.bedandfed.co.uk/ helps you convert your home into a b and b  by advertising any spare rooms you have plus breakast.

You mustn't charge more than £35 per night.
costs £70 to advertising every year

crashpadder.com

selling your own designed clothes

http://www.spreadshirt.co.uk/ helps you create and sell your own designed t-shirts,sweatshirts etc etc

zazzle in another post

Human intelligence tasks(HITS) and innocentive

HITS are little jobs that a person can do better than a computer.eg descriding a photo etc

http://www.mturk.com/ ownedd by amazon is the place to visit

http://www.innocentive.com/
offers cash rewards for solving problems for businesses and charities etc
Successfull ideas could earn up to $1million

site-flipping

This is where you buy a website,develope it by giving the website a better look,adding forums and other features and then sell them for a profit.

Websites like http://flippa.com/ give more details.