Perfect for the Econ 336 lecture on Anarchy, the State of Nature, and Constitutional Political Economy, or for the grad version.
But this would be a close runner-up:

For my 224 lecture on the economics of drug prohibition, but only by allusion:

Anybody lecturing on Economics & Psychology would need this one, or just on rat choice:

Intermediate micro with calculus? They've got you covered.

Hitting a bit of philosophy of science?

I wonder whether they'd sell me ties with these designs....
Does the New Zealand Initiative do casual Fridays? I'll have to check....
Update: Seamus pines for a Locke t-shirt. As he lectures in a jacket and tie, we'll file this under "notional rather than effective demand".