hi, im new to running so im not sure if this is a dumb question or not, probably is knowing me. im going for the london marathon in a years time, my question is, when training how do you know how far you have ran? is there some gadget that you can buy that tells you? many thanks to anyone that has time to answer what im sure is a daft question.

My favorite is the Garmin forerunner 305. There are many other options using GPS (as the Garmins) or the foot pod accelerometers. It's easy to find information about them - just google around or go to the Garmin or Polar websites.

You can log onto walk jog run (http://www.walkjogrun.net/) which is like google earht and you can actually track your distance on a map that measures your distance. Works great for me!

ah, yes, good point. There are also these online options:

http://www.usatf.org/routes
http://www.gmap-pedometer.com
http://www.mapmyrun.com

all use the same idea.