If you are using a SPOT on the trail, there is a cool site that will post your SPOT check-ins on a communal map so that your family/friends can see where you are along the trail when you choose to use the check-in feature. It also shows where you are in relation to other hikers also signed up on this site. It is fun and also keeps a storage of every check-in you make along the trail (SPOTS usually only keep the last 7 check-ins). Great to look back on and see what you've traveled from one check-in to the next. I was even able to embed it to my blog so followers could easily relate my day's post to where I was on the map. If you want to see how I embedded the map for the CDT last summer, here is the link.
http://www.walkingwithwired.com/p/wheres-erin_26.html
I'll soon be changing it to the AT map Here is the link for those that are interested in registering. It's free and they do take donations for the service.
http://www.trackleaders.com/at