So, we finally did it. We've made t-shirts available! Here is the link to the "It's like a sports bar, but with graphs" shirt, and here is the link for the "Vim" shirt.
A couple notes. First, both shirts are available in both green and white (I didn't realize that would be an option before; white is a little cheaper). Second, because these are custom-printed, you get your choice of shirt type as well. For the two folks who made the winning suggestions, I'll be following up with you to get you your shirt.
I'm planning to get both.
Here are the images, to jog your memory:
The Only Colors: It's like a sports bar, but with graphs