What do you do with old gadgets that you no longer use? Give them away to relatives, or throw them in the bin? Argos is the latest UK company to jumpinto the trade-in business, offering cash for your unwanted phones and tablets. Plenty of smartphone trade-in companies operate on the web, such asEnvirofone and Mazuma Mobile, but few have a high street presence like Argos. The company hopes that customers will prefer the convenience of walking into a store, getting a quote and then immediately receiving a gift card that can be used to buy something new. As the Guardian reports, Argos wants to expand the scheme to include cameras, laptops and other electrical devices in the future. Just like Game and CeX, however, its success will inevitably hinge on the prices being offered to consumers. If Argos is too stingy, the convenience will be irrelevant -- people will simply hold onto their devices or offload them through other avenues such as eBay.