There have been a fair few questions about this, and I thought I'd just clarify things.
Yes, usernames can be changed, within reason. If you just signed up, and used your real name or your email in your name, we can fix that for you. I suggest that you don't post until we change it.
Please keep in mind that we're not really inclined to change names just for the heck of it. The primary reason is because if you've posted more than a handful of times, chances are you've been quoted a few times as well. Changing your name will make a mess out of threads where you've been quoted, and the quotes defeat the point of changing your name for personal reasons, as it's still out there. But we fully understand the need for privacy, so that's something we're always willing to work with you on.
Also, please make sure that the name you want to use is not already in use before you send your request.
Scroll down to find a post by Tom, and click on his username to contact him about a name change. Or just post your question here. Someone will get back to you.