Thanks for your help. Hmm. Basically I can see the page MediaWiki:Uselogin and the message on this page says 'Log in / create account'. This is the title of the Log in page but any text I add to this page gets added to the title. I would like to add some text so that it appears below the title but above the login box. Any ideas? Thanks.
If there isn't a message available to edit, you'll have to edit the template at includes/templates/Userlogin.php.
V/r,
Ryan Lane