There are plenty of sites which offer cash for old mobile phones. ReGadget takes a similar approach, but expands the range of gadgets you can send in, covering phones, cameras, MP3 players and consoles.
The site works on the same model as its rivals: identify your item, get a quote, and then send it in to a freepost address. The sum is paid into your bank account once the gadget has been received and inspected.
Depending on your device, this may not be the optimum way to make money from it. For a 16GB iPhone 4 in good condition with original packaging, ReGadget offers $568.66. That's not chump change by any means, but as we established in a recent market check, you can likely sell an iPhone 4 for $700 or more on eBay.
That said, ReGadget's quoted price is higher than any of the other rival sites we examined during that research, and the option to dispose of items other than phones is appealing. Just check your other avenues before committing to a deal.
If you give ReGadget a go, tell us your experience in the comments. (Note: the site seems to be suffering from Lifehacker reader overload and is very up and down right now.)