Set you location by clicking on the tiny "i" in the lower right corner. It took me a while to find.
In one tight screen AccuWeather for iPhone displays the 15-day forecast with the high temperature, neatly color coded to clear, cloudy, rainy, etc. so that you can see a quick summary of the weather at a glance.
Click on the little radar icon in the upper right (watch out, it's tiny) and you get the animated Doppler radar. Clicking on the little clock gives you the hourly weather report.
Clicking into just about anything else takes you the full HTML AccuWeather.com Web page with all the deets. Folks, this is the real deal weather App for the iPhone. I just replaced the Apple icon on my iPhone's home screen with this bad boy.
(Tip: Michael Foglia)
Update: After a counterpoint piece was posted on the PowerPage promoting WeatherBug's Web interface, AccuWeather updated the US radar imagery for their Web app to be location centered at a 300 mile radius, which is better than the previous 600 mile radius.