OK, we've now seen that there is no limit to the length of a username. I think we definitely need one; vroom's
excellent work creating a formatting system for the front page is pointless if usernames like i_had_a_litle_trouble_so_i_came_up_with_this
force scrolling anyway.
What kind of limit should be set? I'm at 10 characters, maleteen2000 is at 12, there are a few other long ones. Some are inconvenient to type, but not drasticly so; so what would be a good limit?
I vote for 13 characters, but I'm willing to be convinced that another length would be better.