Messenger Plus! Live
Messenger Plus Live is an add-on for Windows Live Messenger that adds loads of cool features and extras to your messenger.
Some of the features include custom emoticon sounds, special colour formatting, personalized away status, contact list clean-up, tabbed chats and much more!
Messenger Discovery Live
MessengerDiscovery Live is a free Windows Live Messenger addon that adds over 150 features, settings and customisations.
Some of the features include auto reply, spell checker, display picture stealer and many more.
Stuff Plug brings many cool features to your messenger for free! Features include emoticons stealer, display picture stealer, name editor and more!