If you have an iPod Touch 3rd generation, you can easily update to iOS 5.1.1 by plugging in your device to your iTunes-authorized computer and waiting for the pop up to download and update to the new software. If you are already running an earlier version of iOS 5, you can update wirelessly by going into Settings>General>Software Update.
If you have a 4th generation iPod Touch, then you must update to iOS 6 because you are always forced to update to the latest iOS version available.
I you have a 5th generation, you cannot downgrade to iOS 5.1 because that is not legally allowed by Apple and requires hacks.
iPod download iOS 4.3
YOU DOWNLOAD Evasi0n for ios 6
you download it off of Apple
YOU DOWNLOAD Evasi0n for ios 6
YOU DOWNLOAD Evasi0n for ios 6
you can download ios 4.2 from itunes for free
There is no way to undo iOS 7 after restoring your iPod because iOS 7 is not released yet. However, to downgrade the iOS of your iPod simply download the firmware of the iOS you want from the Internet. While in iTunes, hold shift as you click "Restore my iPod to factory settings" and choose the file you just downloaded and your iPod should be on a lower iOS.
Yes. It is supported
Only the iPod 4th generation can be update to iOS 6. You can update from 4.3.5 by plugging your iPod into your iTunes-authorized computer and accepting the prompt to download and install the new software.
mmm not really
you have to upgrade the iOS to 2.2 or above
Currently there is no ooVoo version for iOS. It will be released soon!