I check nexrad sites and that gives me a heads up as to which way to deviate/fly if I'm getting ready to launch and the boomers are close by.
Speaking of NEXRAD, by far my favorite radar site on the web is run by Weather Underground. There are all sorts of options you can play with (including varying the elevation angle of the scan, using automated storm cell tracking, getting all the gee-whiz independent variables associated with a given cell - like vertically integrated liquid, chance of hail, etc.). Easy to kill a lot of time on this site when storms are rolling through your area:
http://www.wunderground.com/radar/r...ntery=168&lightning=1&showlabels=1&rainsnow=1
The URL above is centered on my house, since all things seem to revolve around me anyway. The cool toggles are on the left of the main display, where it says "Advanced Radar Types" - click that and a menu will pop out. Use "animate map" at the top for a time history, and then at the bottom of the page (under "radar controls") be sure to click "Labels - Show All". If you then scroll down even further on the page, you will see all the data associated with the tracked cells.
OK, enough radar geekiness. Time to go play golf....
(If you don't happen to live where I live, click on the "US Radars" tab at the top to pick whatever is closest to you.)