Only the Ipod Touch 4th gen. canuse iOS4
No, you can use iMessage on a 3rd and 4th gen iPod Touch running iOS 5.
You can't actually 'upgrade' and old ipod touch to a 4th gen. You could sell your old ipod and use the money plus some extra to buy a 4th gen.
Yes
mmm none
It is a video call on the iPhone 4. You can also use it on iPod Touch 4th generation. To use it on iPod Touch 4th generation, have the persons email, and FaceTime their e-mail(only if they have iPod 4th gen. If they have iPhone 4g then just use their phone number)
No but I would highly recommend it
Yeah. You can if you have wifi. You can use facetime skype and other voip services.
yes, you can
No, not like video chat on your email. But of you have the iPod Touch 4th generation you can use FaceTime, which is pretty much video chatting but the other person must have an iPhone 4, the 4th gen iPod touch, or a newer Mac with the FaceTime application.
downloading and playing music, music videos, movies, apps. Ipod Touch 4th gen you can also get face time video calling, take pictures and record videos.
I am pretty sure you can!