What I use is
Weather Underground Mobile, go to
http://m.wund.com/ input your zip code, scroll down and hit "Zoom into animated radar image" and right click on the animated radar and copy the URL. It should look like this
Code:
http://radblast.wunderground.com/cgi-bin/radar/WUNIDS_composite?centerlat=30.49731064¢erlon=-97.82756042&radius=120&type=N0R&frame=0&num=5&delay=15&width=230&height=230&newmaps=1&r=1197408028
Alternately you can take the above URL and cut out the latitude and longitude and add in your own.