Enterprise IM?

Jsf72672 asks: "With the recently-passed Sarbanes-Oxley legislation, and the looming HIPAA compliance requirements a constant thorn in the side of IT staff, Enterprise Instant Messaging seems to be overlooked. Most users are using AIM or MSN. Microsoft and Yahoo! both have products tailored to the Enterprise, but no one wants to rely their technology to keep them out of jail, or from paying huge fines. Jabber looks attractive but our already overtaxed IT staff does not have the time to compile, secure and test homegrown solutions. What are Slashdot-reading IT Managers doing? I found these guys and their InterIM line of products, and they look pretty good. Is anyone using them? Are there other low-cost solutions you have employed?"