The first, in GIF format (for viewing on your computer monitor):
Also available in PDF and EPS (for printing, or viewing at arbitrary magnifications).
Some people complained the above logo was hard to read (although I suspect it is still within the literacy requirements for college), so I made another one:
In GIF format:
Also available in PDF and EPS.
The different colors might be interpreted as the different forces through the vacuum, or cosmic strings in the night sky (but really it is a blackboard viewed from too close).