When I was in Manhattan a few months back, struggling with a stroller down 5th Ave (yikes!) I really wished they made one for toddlers. It would have been heck on the back, but worth it.
I know people who wear their toddlers in slings and other carriers. If you get a good one with 2 shoulders, or a wrap, it's great. But the snugli and bjorn are definitely not made for bigger babies. Our bjorn has been in the closet since the baby was about 15lbs.
We had a great experience in the mall this past weekend. My daugther was up on my back, having a great time looking around or sleeping, and we used the stroller to carry our bags. There were definitely several jealous fathers loaded down with bags while their wives pushed the strollers.