A Modest Effort in Numerical Methods
There are five tee shirt sayings available:

Linear Eq.            - When in doubt, linearize
Continuity Eq       - Continuity is good
Continuity Eq       - Conserve!
Navier-Stokes Eq - Life is fluid
Navier-Stokes Eq - Go with the flow

Each saying is available on a variety of shirt styles (men and women) and on a mug.

The full collection can be found at CafePress at
Tee Shirts