If you use Mac OS X’s Screen Sharing and want to extend the functionality, there are some great tips here, which itself is old news, but one of the problems that I have found since I have been using it for quite a while is that when you add IP addresses or computer names to the ‘My Computers’ section is that you can’t get them to go away from the interface itself.
However, you cam remove them from the controlling .plist, simply goto ~/Library/Preferences and open the ‘com.apple.ScreenSharing.plist’ file with the ‘Property List Editor’ or from the commadn line run open -a "Property List Editor.app" ~/Library/Preferences/com.apple.ScreenSharing.plist. Under the ‘SavedComputers’ tag delete then ones you don’t want anymore.