1)   IM Lock Enterprise 2006
IM Lock Enterprise controls and blocks access to Instant Messaging and peer to peer services. Free trial version available - sets up in less than a minute. Blocks all popular services: MSN Messenger, Yahoo Messenger, ICQ, AIM, Skype,iTunes, and more.

 2)   Comvigo Internet Filter and Firewall Pro 2008
Comvigo Internet Filter and Firewall Software - Messenger Blocker, P2P Blocker, Internet Filter, IM Firewall, P2P Firewall, Internet Content Filtering. IM Lock 2008 is a powerful instant message blocker, internet content filter, and Program Firewall.

 3)   WFilter 250-User License Pack 5.5
IMFirewall Software develops a proprietary next-generation Internet content filtering and Internet monitor software products.