I'm making a pre-release version of the XBOX Friends List Watcher desktop application available for download. You can have the list auto refresh periodically by selecting the Auto Refresh menu item and selected an interval. F5 will refresh as well. If you receive an error stating that the information cannot be retrieved, you are probably not logged into the XBOX Live website. You can view the results of the information retrieval by selecting the View / Browser menu item. Upon signing in, you will need to manually refresh.
If you download this version, please be sure to check back periodically for updates. I have a few plans in mind, but I think that it's ready for it's most basic function; which is to help let you know when your friends are playing the games you want to join in on. If you have any suggestions, either leave them here as a comment or send me a private comment using the contact link to the left.
[note] For those that aren't aware, in order to use XBOX Friends List Watcher, you must have the Microsoft .NET Framework v1.1 installed. You can get this from Windows Update.
[update] Modified download link to point to a dedicated page for this project.