Seeing some of the locations in the "ride from your doorstep" post I thought i'd share my commute: http://www.mapometer.com/mountain%20bik ... 77318.html
about 80% off road - heaven.

all offroad except the last mile.

http://wtp2.appspot.com/wheresthepath.htm

Well you did ask: my commute. Very little offroad other than a stretch through Tooting Bec Common. I could increase the amount off road by using the commons a little more but given I'm always a bit late, and there are many stupid restrictions on which paths you're allowed to cycle along in the commons, I tend not to bother.

7.5 ish hectic miles from south to central London... Good to be on the bike but not a particular joyful ride...!

My commute is only 0.4 miles so not really much to show