How cool is this! http://www.reversebeacon.net/index.
Great for finding contacts on CW and checking how far you are transmitting by searching your own call sign.
I'm Hooked !!
From the website:
'The Reverse Beacon Network is a revolutionary new idea. Instead of beacons actively transmitting signals, the RBN is a network of stations listening to the bands and reporting what stations they hear, when and how well.'