You can also edit the Owner info as you like, then when you type "sig" in a message it will be replaced with whatever you have entered in the Owner info.
Posted from my CrackBerry at wapforums.crackberry.com
I believe you can change your signature. If you go to the verizon blackberry login page from your computer.
Log in there should be an option for changing your signature. I forget the actual link. But just google
It. Hope that's helps.
Options folder > autotext > menu > new > type shorthand (e.g. XX) in replace field > type what u wish as sig in with field. Appears when u type shorthand (e.g. XX) + press space in email & sms text if options > sms text > disable autotext > no.
Imo best 2 put contact phone# in options > owner. Appears in landscape. Useful in case phone lost.