Some of my family came to visit this weekend, and we did a bunch of sight-seeing. Here are the distance estimates, this is definitely a lower-bound of the amount we walked. I tried to include walks that I know everyone did, and left off a bunch of random trips to the store. Distances are in miles.
GRAND TOTAL: 16.9 miles
I'm guessing that adding in more detail could easily add another mile or more. In the end I bet we walked about 20 miles in all. When you trade a car for your feet, make sure you have good shoes!