New Mac, old iPhone

I have a jailbroken and unlocked iPhone (1.1.3) which was synced to a Mac that got stolen in December. I recently got a new computer and was able to transfer most of the information from my old Mac to the new one from a backup but discovered that I hadn't backed up my old iTunes library!
However, to add new music to my iPhone I get the message that the device is synced with another library and I need to erase and sync, etc.
Will the jailbreaking/unlocking be affected by this? And will the contacts, call log, SMS messages be erased when I resync?

I THINK that this situation is similar to when you sync an iPod to a different computer. It will erase all the music, podcasts and so on. Then replace it with what's on the new computer. This isn't a restore procedure so it shouldn't have anything to do with updating the firmware. As far as the contacts and other info I'm not to sure about that...

I'm in a similar situation...all my music is on my iPod, but my laptop got stolen and I've gotten a new one since. I would like to sync all of my music and playlists from my iPod to my new computer.

Are there any apps out there to do this?