faster than pming when you are trying to make a quick trade
but if you had im it would go much faster than pming eachother
for one it would alert the other person with a sound which is much harder to miss than a (1 New) next to your pm box
your thoughts?

not necessary, sorry. you can use irc if you want a messenger for jsp friends.

pm is more than effective for trades.

Look at your PM box more often >.<

Definatly not needed as long as we have the PM box.

just an idea obviously its not required
just would be cool

Already been suggested. My answer, no. Use as PanicAttack said: irc or an instant messenger, even ventrilo is a very effective way to quickly communicate with others.

not really needed since you can write pms or join the irc community

Not needed, reasons above.

The fastest trades I've done have been like 10 seconds, so I'm satisfied with the pm system at least.

Yes, it'd be fun, but it's certainly not necessary =]

not needed + everything written must be logged for at least some time to provide proof in case of scamming.
pm's already do their job good. join irc or use another messenger to communicate with friends imo...