I signed up for an account and chose to use my email address as my username. It's a pretty typical thing to do. Most of my online accounts are set up like this. However, this is a bad idea on Geocommons. On the site usernames also serve the secondary purpose of being an alias, hence using my email address as username made it visible to everyone on the site. Not good. There should be a warning about this in the account setup step. I had to set up a second account in order to fix this. My first account will just be orphaned.