I've recently discovered
Trackr. It's free, easy to use and can be used to track any activity via GPS. IF you've got a windows mobile device and data connection, Trackr will upload your progress in 60 second intervals (you can change this setting, but 60 seconds is fine with me).
You'll need to set up a user name and password on Trackr. Then download & install the software to your device. You can set your profile to public or private (so only friends can view your live & saved tracks).
Another cool thing about Trackr is, if you take pictures with your cellphone and upload them to Flickr while your doing your Trackr thing, the pictures will show up as clickable icons on your Track at about the same place that the picture was taken (Trackr matches the time/date stamp of the picture with the time/date of the track).
If you do any kind of outside activities, you really have to try out Trackr.