Wow. Double Digit Inflation.

I just read an article that was so pessimistic as to suggest double digit inflation as soon as 2009. The author went on to explain that oil, wheat, corn, coal, and copper have increased an average of 300% in the last few years while consumer prices have only increased some 3%. Apparently China is not going to support us forever and will be focusing more on supplying its own population, having eliminated tax incentives for exporting. I'm not so good at math, but isn't 100% per year more than "double digit" inflation? How is that our basic commodities could go up 300 fold and we only experience a 3% retail price increase?