I have created several scripts and tools—here is a small excerpt.
Messenger Plus! Scripts
Bible Quoter
Provides access to bible quotes right in the chat window (supports: ESV, > KJV, NASB, NKJV).
Bing
Searches Bing for a term and displays the result directly in the chat window.
Last.fm Scrobbler
Submits your currently playing media to Last.fm.
LiveSong
Play any song instantly. Simply enter /livesong <title or artist> and press Enter.
Music Notifier
Notifies you when your currently playing music changes.
Plus! VRT Radiospeler
Listen to all stations of the Belgian VRT, directly in Messenger. Built in cooperation with Bram Lancsweert and VRT.
Timezone
Adds a contact clock into the chat window notification area. You can set the timezone for each contact individually.
Tweet2PSM
Updates your personal message with your current Twitter Status, with customizable time interval.
VER Enhancer
Adds other Messenger add-ons with their versions to (!VER).
WLMStatus
Easy web display of your Messenger status, with dozens of different styles and automatic status update.
Other Tools
Clubhouse Tags WordPress plugin
Adds Microsoft Clubhouse tags to your blog feed so your posts can propagate on the Clubhouse website and on affiliated websites.
Messenger Aero Switcher
In Windows Live Messenger 2009 on Windows Vista and Windows 7, Aero is used for drawing the window frames of your contact list and conversation (chat) windows.
TxtBear WordPress plugin
Upload documents in PDF, DOC, DOCX, XLS and many other formats to your WordPress site. Then make them super-accessible to your visitors with the embedded Lightbox Viewer.