Before selling a phone

Hi,

I am planning to sell off my Nokia 3588i on eBay (or the local flea market)
pretty soon.

However, somebody advised me (without any elaboration) that I need to
"clear" the phone before selling it. I am canceling the service associated
with it and deleting all stored numbers and other info. Is there anything
else I need to do? This model does not use a "SIM card".

Is the phone eligible for reactivation with another compatible carrier after
my contract is cancelled on it? My service is Sprint PCS through Liberty
Wireless. I have no outstanding bills or other dues - it is a no-contract
pre-paid service.

Any advice/pointers would be most welcome.

Regards and thanks in anticipation.

JP