Prographics. Across hwy 12 from McDonalds. Adjacent to Starbucks. Haven't used them in a few years but they were the lowest and best quality when I was in school.
Little known fact about the engineering school- they have a poster printer that only engineering students can use. You can get a 3.5' x 6' poster on glossy paper for around $35. I used it a couple of times in school and it always looked great. I think they will laminate them if you ask.
There's probably a few tucked around campus. I used to be "responsible" for one where I worked. It cranked out poster presentations for research association meetings. If you have to sign up and pay in advance, I guess you might be able to get away with printing out "Danny Kannel can go eat a bag of Daks."