It’s fun observing what people are using Google App Engine for.
Sprunge.us provides a pastebin service which you use from the command line. For example I put this script in my PATH:
exec curl -F ‘sprunge=< -' http://sprunge.us'
At that point you can post things by doing
exec curl -F ‘sprunge=<-' http://sprunge.us http://sprunge.us/