There are so many television adverts for mobile phone-buying websites offering cash for old handsets. But the price they pay varies daily, based on the company and the phone. For example, on one day the same 16GB iPhone4 in good condition could earn between £114.07 and £255 (for top condition).
So it really is worth a rummage through your drawers to see if your old handset is worth anything. Do check out at least three buyers - try Envirofone, Mazuma and Fonebank, or www.mobilevaluer.com, which compares 18 different prices for you. The company you choose will send you a freepost jiffy bag to put your mobile in and send it back.
If you have more time you can use eBay, which usually beats the best mobile phone-buying sites.