The iPhoto guided tour can be found here and features John, whom we've seen in other guided tours. It's a fun way to check out the new features that were demonstrated during the keynote, as well as others that didn't make the presentation.
The iMovie tour can be found here, and again features our friend John. We must admit that the animated map is pretty cool, even though we expect it to be heavily abused in the next few months.
Additionally, you'll find tutorials for the new versions of iPhoto, iMovie, GarageBand, iWeb and iDVD here. Check them out and decide if you're willing to pay the $79US upgrade fee.