The great t-shirt hunt...

I am not a great wearer of the t-shirt, on the whole. However, now and again, I see one I MUST have...and, thanks to my librarian friend again, I now have to track down this beauty:

How can I not have this??? If anyone's seen it anywhere easily get-able, please let me know - and if I find it in the meantime, I'll post the information. I can think of the odd person in my circle who might also enjoy it...