I spoke of PropNET in a previous post. Allow me to direct you to more information and the maps it generates to show where the propagation is happening. First, the display info can be had at http://propnet.org/index3rp.shtml . This link will allow you to set up the band and area of the country you are interested in. When you have that set up, click the "Catches" link just under the table.
Now for the software which you'll need to participate in this project. You can find the software here: http://sourceforge.net/project/showfiles.php?group_id=250959&package_id=306760&release_id=671918
leave a comment on this post if you have problems, or twitter me at http://twitter.com/kd0ar if you need more information.