I download the local TV stations Doppler app. it has the option to send weather warnings to your gmail account on the Droid. You can punch in your address & it marks it on the radar screen.
Weather.com also comes on the Droid. I leave it on the "current location" option and the gps gives you current conditions, wherever you may be.
I use radarnow on my Droid. It's a great app because it gives me real time radar. Saved my rear when I was traveling North from Florida last week. I stayed parked as extreme weather passed just North of my location.
I use Radar Scope ($9.99) app on my iPhone. From what I understand it has all the top radar functions that include Doppler . It's fast and it's reliable and it's in REAL TIME. Been using it for about a year now. I also use the Weather Channel free app when I need to know the simple stuff as a back up.