If your a user of Microsoft’s internet messaging / chat client, Microsoft Messenger Live, you should check out a suite of tools from Messenger Plus! Live – http://www.msgpluslive.net/
Add-ons and features include a hide from boss shortcut (great for the office), blocking of groups of contacts, notification of emails from a non-hotmail account, tabbed chatting and many more.
Best of all, these suite of tools are free to download – well worth checking out.

