You have to get used to walking in solid crowds of people - at least if you go to Xiangyang Market on Sunday afternoon. This is the place where, if you are a large Westerner you actually have a small chance of finding the right size shirt or shoes that fit.
On Sunday Xiangyang Market was a solid mass of humanity and I kinda chuckled to myself as I looked over the heads of hundreds of Shanghai locals (being about a head taller than the average) looking for brand name fashion at knockoff prices. Each vendor has their own stall with Liz Clairborne, Nike, Pacific Trail and Dockers covering every inch of wall space. I kind of moved with the mass of people exiting the stream occasionally to check out a pair of shoes or sweater that caught my eye in one of the stalls. Every few minutes someone would come up to me, being a Westerner, saying in a whisper "CD? DVD? latest CD? Very cheap".

I would keep walking that they would go off to find another sale of their knockoff merchandise. In the market I was able to get a fairly nice pair of Nike Air that looked like they might be real (Nike box and all) in size 45 (43 is a 9 and a half and the largest size which nearly every shoe store will go up to). Price 150 RMB (starting out at 200) or a little less than $20. It was a score.
There is something to be said for convenience in the US. It seems like the convenience thing has never really been thought through here. Bring your own bags at some supermarket checkout counter (which is probably a good thing), and bring your own napkins at the dim sum restaurants.