Hiya! I write at wpmututorials.com, and can be found in the WordPress forums moderating the multisite section, as well as speaking at the occasional WordCamp.
I'm also co-authoring the book, "WordPress All-In-One Desk reference available in march 2011 from Wiley publishing.
I also provide BuddyPress support for the Genesis parent theme from StudioPress, in the form of the GenesisConnect plugin.
I'm a full time freelancer and plugin provider (wpebooks.com is where I sell ebooks and plugins relating to multisite) and a WordPress MU user since version 1.1. All told, I've been a WordPress user since 2005.