This application is a musthave, it is called Trayit! and allows you to move an application to the tray by right clicking the "X" button. It allows me to keep Thunderbird open 24/7 without having it use up precious Taskbar space
http://www.teamcti.com/trayit/trayit.htm
Also I reccomend WordWeb. Highlight any word in any application and click on the tray icon to see what it means and similar words. In applications where you can edit text you can replace the word with the correct spelling if you found it was spelled wrong. A must have!
http://wordweb.info/free/
I love freeware and have found a lot of it in the past few years. There are so many awesome apps out there!