Is Instant-Messaging just for the under-30 crowd?  Think again.  Used with discipline (read: with sensitivity to cultural considerations), and once it grows up in terms of:

• interoperability across platforms (AOL, Yahoo, Microsoft),
• archiving, and
• security

it may be just one of any number of media people use to communicate depending on what they're otherwise doing, the urgency of the communication, and their "degrees of intimacy"—meaning one partner replies to another partner as fast as to a spouse.  But that's another column.

Does your firm currently ban it?  Perhaps a re-think is in order.   Restrict it?  How and why?   It will soon be time for a conscious and considered IM policy, if it's not already;  IM is not going away, and like many other aspects of the technology arms race, it will only become more functional and powerful over time.