If you are a regular Google Chat user (on Gmail) now there is a way to know if your buddies are chatting from an Android Phone or device using Android Chat. Your chat buddies will show up as robot icons when they chat from Android.Shirley is online with Android, Nicolle R. is using regular Gmail chat, and Chris I. is currently away but also on Android. Slatka is not an angry robot — she's online with Android but currently busy.
I think it is better because you can send a small precious messages to those who are on the Android phones.
But I wonder if the users are utilizing those upcoming Android based tablets and netbooks need to have shorter messages, they can chat like any computer based chat user.
In any case it is a nice variation from those dots!
Official Gmail Blog: New in Labs: Green robot icon