I really try to avoid buying any food with ingredients made outside of the United States--with the exceptions of food from Italy, Greece, or France (usually those are specialty food items, like olives/olive oil). It's hard to do, but it can be done--buying organic packaged foods helps (when packaged foods need to be bought), but since the tainted toothpaste I've been checking everything we buy, and trying to buy more local, fresh food. We go to Saturday Market every week in order to get fresh fruits and vegetables (I'm really paranoid about fruit from Mexico) that are locally grown. We have a food co-op here that marks everything produced within 6 counties around ours. The food co-op is even working to find a local wheat crop so that they can produce bread that fits within that designation.
I did the not buying things made in China for about three years when I was a teenager. It has gotten a lot more expensive since then to not buy things from China.
In another thread, I posted an article from the New York Times that details exactly which countries have shipped unsafe food to the United States:
http://www.tfproject.org/tfp/showthread.php?t=120936 It's not just China. It's India, Mexico, the Dominican Republic--and even Denmark. Just more reason to eat locally!