This is a confusing question...if you already have an ipod touch2nd gen, it should already be synced to your computer. And all you should have to do is sync your new touch and get the option to restore if u hae a backup of the old one. Also unless u r specifically trying to get itunes purchases off of your touch 2nd gen , then all of your music should be there.

My suggestion : take your old ipod touch, sync it to your comPuter and create a backup of it. Then sync your new touch and use the restore option and set up ur touch with the backup you have of your old one. Follow me?