This may be old news, but just noticed it's now possible to view additional data on Wunderground's dashboard - here's mine:
http://www.wunderground.com/personal-weather-station/dashboard?ID=ISCOTLAN25Note they are showing leaf wetness, soil temperature and moisture!
I've often wondered what they do with the additional data we send - now at last it looks like they're starting to use it.
(Note - there does appear to be some bugs - mine's not currently showing (what I consider to be the most important variable) pressure, and the number of decimal places on the soil temperature seems a little excessive
)
[Edit: It seems the problems on the page only apply if you are using centigrade and mm's - it all looks fine in inches and Fahrenheit]