I gave away my Sony Ericsson P800, for which I had original box, manuals, charger and 3 spare styluseseses. If I'd kept it, I could now be RICH! After all, it didn't even have GPRS... The friend I gave it to was still using it well after the iPhone came out.
Sadly I also got rid of my Motorola MicroTac years ago. Although I think the 'micro' was a bit cheeky in the name, as a belt clip or bag was the only realistic way to carry it. I miss the days of having to pull up the aerial before making a call, and then flip the phone open. Well OK, maybe not the aerial bit, particularly as there was a point when some of those were fakes and the phones had internal antennae. But I really do miss the flip-phone format. No-one seems to do them any more, which is a real shame.