I just completed the course "Developing Microsoft SharePoint 2007 Solutions – Part 2: Advanced" at U2U last week.
The course covered some of the most important development topics of SharePoint, like WebParts, Features, SiteDefs, Application Pages, BDC and more.
Our instructor was Serge Luca, who turned out to be a great guy with a lot of knowledge about almost every aspect of SharePoint (and especially workflows that is).
So, thanks everyone for the great week, and I hope I'll see you all soon again 
nsevens