Wow, thanks for the links!
de nada. (If you're going to live in San Antonio, you'll have learn a little Spanish lingo, assuming you don't already speak it. de nada means literally "of nothing" but can be thought of as "it's nothing".
The long time/mulit-generation Hispanics often speak a sort of Spanglish. A few words of Spanish thrown into what is otherwise English, just for emphasis. And to irritate us Gringos.. sometimes. :) Actually San Antonio is the friendliest *city* I've ever been in. Even when one is a member of a minority group (in my case "gringo". :)