Trillian .7 is great... Even the transparency option works well 
For those with rule-sets and/or firewalls....
AOL AIM:
64.12.0.0 ~ 64.12.255.255 :5190
205.188.0.0 ~ 205.188.255.255 :5190
MSN:
Port :1863
Yahoo Messenger:
Port :5050
I don't remember the 
network range for MSN or Yahoo. If needed, I will look those up and post back (I only remember the AOL/ICQ IP's by heart).
Also, allow :80 to each service depending on your needs....
FYI: My "handle" for all the services is 
docdoo99 