I used my new amazing regular expression super powers to limit user names to alphanumeric characters only. Underscores are also allowed. The point of this is to stamp out user names with spaces in them for a reason I'd explain were I not so busy. It has to do with URLs. Speculate wildly amongst yourself.
Anyhow, I've consulted with Big Evil Dan and he's okay with the idea of my changing all spaces in user names to underscores. ie. Big Evil Dan may soon be Big_Evil_Dan. If any of you folks with spaces in your usernames have any well-reasoned objections, object on.