Most of my "industry contacts" get to me through icq... but I prefer the speed and stability of AIM (which is what my mainstream affiliates and collegues generally use).
What I DO like about ICQ over AIM is the fact that if I miss an icq msg/get logged off before reading, etc. the icq message is still there when I relog on... w/ AIM, I might never know that someone has tried to contact me....
And I NEVER want to miss important messages from DEREK!!!! 
Cheers!