You can do this with mod_rewrite.

I got in contact with the owner of mingleville to ask him if he used mod_rewrite and he does.

this is a rule that i have got so far:

RewriteRule ^([a-zA-Z0-9]*)$ /profile.php?view=$1 [L]

But the only problem i have at the min is that even if it is that when u access the site it automatically redirects you to the profile page

*EDIT*

I have now finished the rule and it works!

RewriteEngine on
RewriteRule ^$ /index.php
RewriteRule ^([a-zA-Z0-9_]*)$ /somepage.php?someuser=$1 [L]
ErrorDocument 404

You can see it in action here:

http://labs.mxgames.co.uk/crouchy

Hope this helps.

Cheers

Matt