In honor of the first day of classes of St. Louis University, I've put together a Google map of various spots near the SLU campus where students can find relatively cheap food. This isn't meant to be comprehensive, nor can I personally vouch for each place. Consider it a work in progress. If I missed something, please let me know, and I'll add it.
I'll put together something for Wash. U. later this week.
Also: Click on the "View larger map" link beneath the map to see the complete list of restaurants alongside the map -- it can help separate some of these "thumbtacks" that are close together, like Pappy's and the U.