fergbrain wrote: Wordpress
Wordpress is an engine, not a hosting provider.
Wordpress is an engine. Wordpress Multi User is a hosted solution for Wordpress 1.6 alpha (not stable yet). Wordpress.com is running WPMU.
And, yes, my recommendation would be to go with a hosted WP solution. It should provide you greater features, greater flexibility and greater portability should you want to move the blog later.
Getting an invite is pretty easy. Just ask one of the dev guys