Heh, this was the first (well...sorta) Threadless shirt I brought. I was going to wait for natural to come back...but then I just decided to go for blue, and I'm glad I did or else I wouldn't have a shirt.
Heh, I have a humorous image of threadless employees dashing about, begging people for t-shirts to print on.
Oh and the send in your own t-shirt idea would be amazingly inefficent and costly.