Yea, I personally hate Walmart myself, although, thanks to Tom, and being really cheap yesterday, I've been there twice in the last month. But anyway, I'll play devils advocate on this one. As much as Walmart has hurt the US economy (loss of jobs in smaller retail and manufacturing, lack of health care, abuse of employees) it has been even more helpful. It has brought well need competition to the market by, as said before, weeding out less completive, less efficient businesses. It has also help the US become more competitive on the world market by weeding out the lower tech, lower profit manufacturing businesses. A lot of people complain about them driving manufacturing over sees and the loss of jobs as a result, I'll argue that it is a good thing. For one, it lowers prices on goods to such an extent that, I've heard, it saves the average US family something like $1500 (don't quote me on that number) even if they don't shop at Walmart. Second, it moves lower quality, lower paying manufacturing jobs over sees, which forces some of that population that once held those jobs into training and higher skilled jobs. With an unemployment rate below 5%, no one can blame Walmart for not being able to find a job. Thirdly, when those manufacturing jobs move over seas, they help stimulate the local economy, driving economic growth, there by increasing demand for the more highly skilled product and services, which are the mainstay of the US economy.
There are also additional benefits that Walmart provides. There push to sell more compact fluorescents could help stop millions of pounds of carbon from going into the atmosphere. Also, they are demanding there truck suppliers increase the efficiency of their trucks by some 33% (again, don't quote me on this number) in the next 10 years. Because of their size and influence in the market, this we inevitable cause the majority of the truck market to adopt these standards.
So yea, in ways Walmart is evil, and I avoid shopping there at all costs, in the end, there good for us, IMHO.