On a non-jailbroken phone I dont think so. On a jailbroken one you can use something like iphone backup extractor or juicephone and manually take what you want from your backup and put it back on your phone.
I've found something called iBackupBot which claims to allow modifications of the backup file but I'm not sure.
This doesn't seem like too complicated of a task. I just don't want to restore *EVERYTHING*
EDIT: Does restoring a backup automatically resync all the applications you had installed? If not, I wonder if I only sync specific applications what would happen?
I wonder what's actually in a backup file anyways... I've always been skeptical of un-jailbreaking my phone and restoring a backup because it seems like a lot of "garbage" would be restored to the phone...