You can't just throw old phones in the bin because of the environmental impact

Mark Harrison of Isis

But there's a growing demand for abandoned handsets. Oxfam has launched an appeal for old mobiles to raise money for charitable causes.

Each handset is worth between �2 and �20 to the charity. A Nokia 5110, for instance, pays for 24 school desks for children in Kenya.

Many of the abandoned mobiles are exported to African countries with poor landline infrastructure, says Mark Harrison of Isis Telecommunications, Oxfam's partner in the scheme.

"New mobiles can be very expensive, so these second-hand mobiles are much more affordable."

Ringing the changes

When a phone is donated, Isis staff wipe any stored numbers, remove and destroy the SIM card if the donor forgets to take it out, and refit and repair the handset if necessary.

Not all phones can be reused

Those that are well and truly obsolete are stripped for parts and disposed of safely, to prevent the batteries leaking cadmium - a dangerous toxic substance - into the soil.

"You can't just throw old phones in the bin because of the environmental impact," Mr Harrison says.

Isis has been in the business of recycling old mobiles for three years, mostly for companies upgrading their handsets to newer models, Mr Harrison says.

A similar scheme is planned by the Scottish recycling company Eurosource, which will allow donors to pick a cause to receive the proceeds.

Reduce, reuse, recycle

About 4m replacement phones are sold every year in the UK, yet most - often just a year old - are discarded.

"Take my old computer, please!"

Although mobiles are not covered by an EU directive which requires manufacturers to collect and recycle their products, adding them to the list is under consideration.

The waste electrical and electronic equipment directive aims to cut the millions of tonnes of electrical junk - from televisions and fridges to computers and video recorders - that Europe produces each year.

Just as Oxfam's scheme finds new owners for old mobiles, other schemes collect old PCs to give to the digitally deprived.

Which just goes to show, what's junk to you may be a godsend to another.

For details of how to donate your mobile, see Internet links.