John Porcaro just blogged a great piece about using IM for work

The last place I worked at had issues with IM use that were never really clear to me.

Our IT director insisted that because it could not be logged centrally(this was before LCS) it should be blocked so as to avoid any potential lawsuits

I believe its still not allowed there which i think is rather bizarre as the company in question would certainly benefit from the increased productivity that such a technoogy would provide.