There are several ways.
1. Download a Cydia tweak called MyOS.
2. Put into the system files. This also allows you to use it when in same mode. You have to edit the file /System/Library/CoreServices/SpringBoard.app/N72AP.plist
You do this in iFile. You use the text viewer. Scroll down until you see that it says capabilities. You then add
homescreen-wallpaper
and then it gives you a homescreen wallpaper no matter what.
Do the same for multitasking. Just instead of homescreen-wallpaper, put multitasking. Must be in all lower case to work.
Yes, you can put music on a jailbroken iPod Touch.
you cant
Yes, the iPod Touch with the 2.0 software can be jailbroken.
yes restore it
I guess
settings/wallpapers
Once jailbroken, the iPod Touch's one year warranty is void.
No...
Not without erasing the jailbreak.
it is battery
A jailbroken iPod Touch is certainly legal. However, the act of getting every app in the App Store for free (the ones that require payment) is illegal.
Currently, the iPod Touch 3rd generation cannot be jailbroken because it has a built-in firewall of sorts, a measure taken by Apple to prevent the iPod Touch from being jailbroken. There is a jailbreak software currently being beta-tested, but is not ready for public use.