For those of you haven't checked them out yet, The videos that Randy suggested int eh forums by Ted Pattison are a pretty good introduction to developing SharePoint Web parts for V3/2.0
What struck me as I walked throug hthe first video, is that Microsoft has not really given you a way to graphically design web parts STILL. It seems that you would have to use the "Smart Part" methodology to develop user controls in ASP>NET that can be hosted as web parts. Or am I missing something ?