Newsweek has an interesting interview with a "coyote," someone who smuggles individuals over the border into the US. A few telling questions and answers:

What's the going smuggling rate today?
We charge $1,800 per person. That's standard now. It was $1,600 not too long ago, in 2004 and 2005. That money is split up between about seven or eight of us who work together. I earn $300 from each trip and make a trip every three days. We usually take across a group of eight or nine people. They used to be much bigger. When I started this three years ago, there'd be 15 or 20 people crossing in one group. I made $700 for each trip back then. It's changed now that the United States is adding more security. Fewer people are coming up to us now.

Who's crossing?
People from all over Mexico and then Latin America. Lots of Central Americans, Brazilians, people from Asia.

What about the Mexican drug cartels and reports that they're now muscling in on human smuggling?
It's getting bad. There's a lot of pressure on us here to work with these other groups. We can't really go at it alone anymore.