This is specifically a link for people in the UK, Ireland or France.
If you have an old mobile gathering dust in a drawer, why not recycle it and help with the appeal for the Asian disaster?
Recycling Appeal is a licenced operation for recycling purposes, and I'm sending them my old Nokia which will do more good than trying to sell it on EBay! Envelopes to send in old phones and also printer cartridges are available from that page.
It is also a reputable organisation, and supports a number of other organisations such as the Roy Castle Lung Cancer Foundation and Marie Curie charity. More details here, with a list of partners and charities which have already received cash.