This is probably a nice place for a quick explanation of Jabber servers and JIDs. There are two parts to a Jabber ID, or JID. The first part is your username, and the second part is the server address. The JID is written like an email address: username@server.com. You can choose any username that you want, but keep in mind that it might already be taken 
Here is how you do the registration with for instance Psi:
On clicking on Register New Account previously, a new Register Account window appears as below.
In the Register Account window, type the name of the server “jabber.no”. Click on the drop down arrow on the right of the input field will retrieve a list of Jabber Servers from xmpp.net automatically.
If you entered your server correctly, then Psi will pop up a dialog asking you for a username and password.
Choose any username and password you want. Remember that the username and the server combine to form your JID. If the selected username already exists on the server, Psi will pop an error. In such a case, you will need to specify a different username.
After successfully registering an account, Psi adds the account to your roster automatically and you are good to go. Remember to tell your friends your JID so that they can find you.
Hva er dette?
Hvor registrerer jeg meg?
Hei, du registrerer deg ved ÃÂ¥ installere Gajim eller Psi. Registreringsskjemaet er ikke i orden lenger ;|
very good
Can I delete registered account?
Yes you can. Just delete the account from your XMPP client and it will ask you if you want to remove the account from the server as well.
Thank’s for account! Sounds wonderful…jabber.no!!!