I've just release a new version of SQL Internals Viewer, a tool for examining SQL Server internals.
If you haven't seen the application there is an introduction to it on this website here[/url].
There are several new features that have been introduced since the article was published. The very latest features include support for SQL Server 2008, including row and page compression and sparse columns.
The application is available to download for free from www.sqlinternalsviewer.com