Atomic Learning has posted over 40 video tutorials covering the new features introduced by Tiger.
The tutorials cover Spotlight and Dashboard (the obvious), along with several other features new to the Mac OS. Videos range from introductions to more in depth looks that should help you get the most out of Tiger's new features.
Of course you're a Tiger pro and don't need any help using your OS, but you never know. In any new OS, there's always room for learning new things long after you think you know it all.