You can send outbound emails with JetConnect. It's not equiped for you to receive emails yet though.

You can of course also send text messages to other folks text devices and cell phones. You can also Instant Message with most of the popular IM systems (AOL, MSN, etc). I usually have live IM converstations with my ladyfriend, but have also been known to bug a few FlyerTalkers from the sky, as well.

I love it as I can catch up on the news, but mainly for the email and messaging functions.

If someone else you knew were on another 767, I would imagine you could IM plane to plane!