Do yourself a favor and dig some change out of the sofa, then head down to Sol del Sur 3268 W Fullerton. For $1.75, you can get a delicious al pastor taco (they put pineapples in it, to balance the saltiness).
I think this place is new? At least, I'd never noticed it before. Looks like they are waiting on a liquor license, too.

Sol Del Sur
3268 W Fullerton Ave
Chicago, IL 60647
773-384-8869