For every user’s page on Twitter, you’ll notice a 6 x 6 area of profile images of the people they are following. Here’s mine:

Just in case if you ever wanted in what order they’re in, here’s a page on Twitter’s GetSatisfaction page on this same topic. It’s based on when the user signed up.
But this is when I started to think… maybe people will start selling and buying earlier-signed up accounts in an effort to increase visibility. I mean, Calacanis attempted to buy a slot on the “Suggested Users” list for $250K. (I can’t help but associate this kind of “shadiness” with the buying and selling of WoW accounts.)
This is only made easier by how easy it is to change your name on Twitter (a feature which, I think, ends up making me think more about online user accounts in general).
Just as a little easter egg, to find out when a specific user joined Twitter on Twitter itself, you can use the “whois” command after you’re logged in. Try it.
whois joshkim

And that ends today’s tidbit on Twitter.
I’ll sell you my position #3 on the 6×6 line up for $5000 USD.
I’ll also gift wrap it with a pretty bow.