I restored my 3G a few days ago because I had forgotten the pass for my lock. It wasn't jailbroken or anything and I did back it up. When it was all done I still had my contacts, pictures, notes and SMS chats but no apps! I can get the ones that I paid for free though since itunes know that I previously bought them. So yes I would recommend restoring it and maybe not bothering with jailbreaking it again.