Hi Brian,
I was sniffing around a weather site that is near my house and that uses VWS and they seem to have added a lot of interesting web reports - visit http://home.nc.rr.com/bbooth/daily.htm to see examples such as:
Noaa yearly report
Yearly archive report
Montly archive report
Daily archive report
I think some of the last 3 could be done with existing custom html tags,but not all e.g. mean/average values for a day/month.
I was also thinking it might be fun to have some custom tags to look at the weather a year ago on this day!
Just some ideas! Always good to take a peek at what the competition is doing!