There are plenty of companies out there who offer cash to buy your old mobile phone, but newcomer ReGadget is expanding the offer to include all kinds of gadgets, from cameras to games consoles to MP3 players.
Depending on the condition of the device, whether or not it still works and things like peripherals and the original packaging, the amount of money you can get from recycling your old gadgets is actually pretty good. As Gus over at Lifehacker points out, the amount you can get for a good-condition iPhone 4 is better than the other mobile phone buy-back offers out there, although you'd probably still make more money selling it on eBay.
If you do have a heap of old gadgets lying around unused, it could be a good opportunity to both clear up some clutter and make some cash, with the added benefit of knowing that your gadgets won't be going into landfill. As we've previously pointed out, recycling is the best possible way to do your bit to save the planet.