I have a T650 (good order, no problem) that I would like to exchange for a Sony Ericsson (K800i, W850i or W810i). Reason is that I now have a Blackberry for work, and a Blackberry + a 650 is not very practical...

Not suprisingly, I also have the Plantronics 510 headset that works perfectly with the Treo, would be willing to give it also as part of the deal.

The Treo works well, no problem. It is locked on Orange UK and was bought last year. I still have the box, manual, etc.

Best would be to exchange it with someone in London so we can meet in person.