Removing WP-ADMIN bar/dashboard for signed-up users in WPMU

I want to know if it is possible to completely remove or hide the WP-ADMIN bar for users in multi-site, and instead, have a customized dashboard for posting, searching & categorizing posts.

I know there's an easy-admin plugin somewhere here, but I want to know if it's possible to make a WordPress multi-site that does not "feel" wordpress and does not have the default "wp-admin" bar/dashboard (but to be more similar to Tumblr, Blogspot, other multi-blogger platforms...)
and if it's possible, how can I go about doing it?