How to change username in Google Wave
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.
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 firstname.lastname@example.org.