Sometimes I feel out of place when going into a LBS but it all depends on the people. If I want to buy something and don't get any help I walk its just that easy. I do look around and see what the sales people are doing. If there busy I'll give them more time to get to me then someone thats just standing around doing nothing.
I was in a Walmart the other day and saw a rack of those 'Perfect Pushup' devices that they where selling on TV pretty hard for a long time. I was wanting to try them out when I saw them on TV and being 340lbs I wanted to make sure they could hold me before buying. While I was holding the box two employees started snickering and I saw one pointing out of the corner of my eye. I pulled them out dropped to the ground and busted out 30 pushups right in the isle. All I heard then was a whispered "holy s**t". That made me feel good.