If you want a unique nickname for the Apple Game Center service coming in iPhone OS 4.0 you most likely want to install iPhone OS 4.0 right away! Because it is already possible for developers to sign up for the service and reserve the best nicknames!

*Update* iPhone OS 4.0 had quite a few more issues than I expected so I downgraded back to 3.1.3. If you do not need 4.0 for development I’d recommend you wait with installing it…