Actually there is a user who wrote the FB integration already - he put it here: http://leuhusen.net/facebook/rungps.html
Would be nice to see it integrated in the gps-sport.net website!
add me to the wanted list. With nike+ all my runs are posted on facebook, now waiting for run.gps to do the same. Another nice gadget would be that the "follow" feature would be posted on facebook when I start a new training and not just a mail send to the mailbox of the person who wants to follow me