Yes, you can "Undo" a Jailbreak, by going into iTunes and Restoring your iPod Touch, or iPhone.
You cannot put themes on an iPod Touch without the jailbreak.
Yes u just have to jailbreak it
you can download free films off the Internet on your computer and then sync them to your ipod touch but to get free games that you would normally have to pay for u will need to jailbreak your ipod touch first
How to jailbreak my iPod touch
Not without erasing the jailbreak.
It depends on what software your ipod is running.
To jailbreak an ipod touch or an iphone, i recommend using blackra1n from blackra1n.com Have no fear when Jailbreaking because it is a soft mod, and can be restored using the restore button on itunes.
you need 4.0.1 to jailbreak it
itunes. With an ipod touch you can even access itunes without the use of a computer gregory
No, but if you jailbreak your iPhone/iPod Touch, you should be able to. And, I think SEGA has games on the iPod/iPad/iPhone whereas Nintendo has none on iTunes.
Yes, but downloaded apps from Installous will not sync with iTunes.