Thought this website might be of interest to paddlers here.
basically it uses Viewranger mapping software to send live beacons while you are on a hike, bike ride or paddle. Those beacons are then plotted on a map in real time using the phones data connection but it does support other mediums such as Spot and Yellow Brick.
Any tweets from your account are also plotted, real time on the map along with any pictures tweeted. When you get back from your adventure you can link various media accounts such as Picasa to the map, again potting them where they were taken (to the nearest beacon). In addition you can also upload a GPX file to improve the accuracy of the plot on the map.
It all works rather well and last week I paddled the Great Glen Canoe Trail, with my Vieranger beacon set to transmit my position every 10 mins. The Great Glen has pretty good mobile coverage so most of my beacons came through in real time. when out of coverage Viewranger stores the beacons for sending when in coverage.
here is my paddle along the Great Glen, complete with tweets, Picasa pics and GPX uploaded after the trip.
it looks like this
So you get
Real time tracking via GSM or Spot/Yellow Brick. This site is free but your tracker may need a subscription
Media import from sites like Picasa
Lets people track your progress as well as review the trip afterwards, pretty neat.