BuddyPress

You mean that the secondary sites’ themes must contain do_action( ‘wp_footer’) ? Where?

Unfortunately it doesn’t work for me in the way you suggest. The admin bar didn’t show if I use the normal Twentyten theme for slave sites.

Let me know how it works Buddypress… I have a WP 3.0 Multiuser install with Buddypress 1.2.5 and I wish to have a network like Wordpress.com. I need a common admin bar for all the network sites, so the users coming from the other sites can access to the network services (groups, forums, activity, pm, [...]

Thanks a lot. Now it works perfectly.

@Andrea_r: I have some avatars visualization problems, like these:

http://www.grillo16.org/blogs/

http://www.grillo16.org/members/

http://www.grillo16.org/members/admin/blogs/

How could I solve them?