Have been out for a couple of months with a back problem and subsequent operation but am getting back into things now. There was a useful webcast whilst I was off showing the power of the dataview web part:

http://msevents.microsoft.com/CUI/WebCastEventDetails.aspx?EventID=1032256050&EventCategory=5&culture=en-US&CountryCode=US

which had a couple of really useful things in. Maybe I am being blind but I can't see how you can rerun this webcast from this page...

One thing was passing parameters through to the dataview which I think is also covered in someone else's blog and there are details of this here:

http://support.microsoft.com/?id=831093

I've now used this a couple of times and it's really cool - for example if you want to pass 2 dates through to a calendar and only show the entries between those two dates.