Seriously. I've only seen one of these aside from the well-known Livejournal one, and it was fantastic. I don't care who it is(But Sherlock and John would be good), which website they met on(can be unnamed) or what pairings, so long as it's internet-friends-eventually-meet-up style.

Bonus points is Mycroft is somehow involved and you can somehow use the terms "mad hatter" and "hunky dory".