Jeremiah Owyang joined Twitter 1 month (December 2006) before me (January 2007) and Gary Vaynerchuck join in May 2007.
How do I know? A sweet little application from Neville Ridley-Smith (@nev) called ‘When Did You Join Twitter’. I wanted this data a few weeks ago when I wrote the piece about the success of Gary’s marketing tactics, but did not have a nice quick way to get it. I tweeted my request for the info and now we can all get that little morsel of data whenever we want.
Neville said he did it by using a bit of programming to find the first tweet in a users stream.
Cool… nice job Neville