Thanks Penguin3107. I'm assuming you do this sort of thing for a living (?), since you are very, ah, assured in your response!
I was sure there *must be* a way for the BES Admin to view and log Yahoo IMs since several at Crackberry say there is, but I figured it simply wasn't a simple "default" setting for them or that they had to go to extra lengths to get it set up. Nice to know that there just isn't software for that...yet.