Surveys usually pay between 50p ($1) to £3 ($6), although a few pay more. I think they are worth doing - if you do enough of them you can build up a reasonable sum of money. It takes a couple of months to build up any money and you will get screened out of at least half of them which can be frustrating. Some sites "reward" with entries into prize draws, and some reward with shopping vouchers.

If you are interested I have reviewed some of the best survey sites on my website - Extra Cash Review.