Forget the wall. People can climb over them, burrow under them or just drive right through them. What we need is a minefield, a mile-wide minefield. It sounds dreadful. The mind immediately visualizes a poor Mexican peasant desperate to get a landscaping job in Phoenix blown to bloody bits by an exploding mine. One hopes the poor Mexican peasant will visualize the same thing. Then he/she might have second thoughts about trying to enter the US illegally. Heck, he/she might even apply for a permit to work in the US. It would sure beat being blown to bloody bits.

Update: My co-blogger had a better idea, including a minefield, if required.