Here's a guy who talks about shopping with his Brompton: http://www.nycewheels.com/brompton-review-steve.html
I don't have a bag/basket attached to my Brompton yet but I can attest to the usefulness of the EZ-Wheels in my ability to wheel the bike inside the office bldg I work in. The bldg's groundfloor is like a mall where I have to walk quite a bit to get to the elevator then to my office on the 4th floor. With the EZ wheels (my Brompton has a rack), I just wheel it all the way to my cubicle. I don't see how this could be different if I was inside a store or a bookstore with a basket attached on the Brompton's carrier block.
Edit: Here is what I am talking about...
I usually take videos of my rides (on the road bike) with my GoPro HD cameras. This was one time I decided to take a video of my commute on the Brompton.
Last edited by cyclocommuter; 04-15-11 at 06:00 AM.