When I was invited to Google Wave a horrible user name was created for me, because I once choose to sign up for an gmail address with that name just to test GMail spam filter against some subscription functionality I was currently developing. This got me to research how to change the username that is given and I found the following solution.

Edit your profile

Go to your google profile and press Edit Profile. If you're not logged in you'll have to authenticate yourself.

• http://www.google.com/profiles/me

At the bottom of this page you should be able to change your profile URL. When you do this you will also change your username inside Google Wave. It required a restart of my browser before the change went through. I'm not sure if it was just a delay or if they caches your user name with Google Gears or some similar technology. * Note: I did not loose any waves or contacts that I'd set up before the change. Happy Waving! You may now reach me at mikael.lundin82@googlewave.com.