Hey just wanted to pass along these sites to ya. I've found them very useful.
HeyWhatsThat Path Profiler: www.heywhatsthat.com/profiler.html A google maps hack that lets you select point A and point B, and it shows you all the topographical objects in your way (hills). Its good for radio signal propagation estimations.
Antenna Tower Search: www.antennasearch.com Another google maps hack that shows all the local antenna towers and who they belong to.