Did you get a shiny new phone or tablet for Christmas? Is your rubbish old one just lying around not doing much? While it might not be of use to you any more, you could give it a whole new lease of life by donating it to an Open Device Lab, where it can be used to help developers test mobile websites and apps across a wide range of devices.
Because sites and apps don't always work as expected, especially across various mobile devices (there are over 20,000 different models, with around 15 new ones being released every week), testing across a representative range of platforms is, on one hand, a must, but on the other hand it can be expensive. Which is where Open Device Labs come in; there are over 90 of them worldwide and they provide free device testing pools for developers.
