IM on the iPad is in a rather sorry state right now. Ironically the free AIM client, which I normally avoid like the plague, is the most usable option for me.
Current Options
AIM works reliably and is free, but it only connects to AIM and Facebook chat. It occasionally jumps to a past point in the conversation and has to be manually scrolled to the end. This is annoying but forgivable.
IM+ is not free, but it supports multiple IM services (AIM, MSN, Jabber, etc.) However, it occasionally forgets it’s already logged in and warns about multiple sing-ins. Again, annoying but forgivable. The real problem I have is that it doesn’t seem to be usable at all with a keyboard attached. It seems that the message entry field is directly connected to the on-screen keyboard, so when the keyboard his hidden you don’t have a field to type in. And apparently when the device is sitting in my iPad keyboard dock, the on-screen keyboard is not only hidden, but can’t even be activated! The button to restore the keyboard does nothing at all. Hopefully this quirk will be fixed in an upcoming update.
Future Options
Beejive is hopefully coming soon. This is my favorite IM client on iPhone and iPod touch. It has been dead reliable and is very polished. But so far it has not been enhanced to take advantage of the iPad’s larger display.
iChat is probably coming as an avenue for video chat, but it won’t appear until iPhone OS 4.0 hits the virtual shelves.
So far, I haven’t much taken advantage of IM on the iPhone either. I guess I’m selfish that way… my family & closest friends can call or text me if they need to reach me. Twitter’s a less immediate, but usually reliable, way to reach me since I tend to check it when I have a few spare moments.
Video chat on the iPhone — or the iPad for that matter — has some interesting possibilities…
My use of IM on the iPhone was relatively limited, but with its keyboard dock the iPad has taken on the role of netbook for me. That means I’m using it for most of the general-purpose tasks I expect of a computer, including instant messaging. I love it for that, but the tools definitely need a little work.