Nectar

Joining Nectar is free and rather fun- because nectar bargain hunting is an addictive hobby. Nectar works rather like a supermarket loyalty card except that there are many different ways to collect points.
As a general rule, if you are offered a cash benefit in return for giving up the Nectar points, you should so so. I will tell you how to do this in another post.
Nectar points can be spent nearly as easily as cash. You can walk into some stores and charge items to your loyalty card as if it were a credit card. Neat.
Never buy anything just for the points! Having thousands of points can make one feel rich because they are worth only half a penny each. This is how they hope to get you!
If you have a PC, download the toolbar and get paid (in points) to surf!