What are towns or cities on the U.S./Mexico boarder?

I have heard of people living in one country and traveling back and forth for work. What are cities that this can easily be done in, and how would you go about doing such a thing? I am speaking as a U.S. citizen, and working and living legaly in both countries. What are good towns or cities to live in, and what are good towns or cities to work in? I do have family that work for GM that could refer me to a good position since they are in upper management, and have heard of a factory, that is on the Mexican side of the boarder, do you know where this is? My question is more about how people do this, where do they live and work, what kind of documentation do you need as a U.S. citizen, I have family in Mexico that could obtain property and living arrangements for me on their side if that would be better, How easy is it to do this. If I was to do something like this, I would probably own property housing on both sides, eventualy, and would probably like to work in the US, is this possible?