...do an esn swap? Will vzw do it for me if I found it, or can I do it online. If I do an esn swap, only my number will be put on the new phone and nothing else right? Thanx for the help!

works like this
call verizon and ask them that you want to do an esn swap
don't tell them you found the phone but instead that a friend gave it to you
if the esn is clear (not declared lost or stollen) then you will be able to use the phone
on the other hand if it isn't clear then you can't activate it
mmm if so you can just use it as a toy for the kids or something like that