I hadn't even heard of Uber until just a few months ago, when my friend told me he had signed up as a driver to supplement his income. My wife and I finally used it during our vacation in Boston earlier this month. While we saw the vast majority of the sites and attractions on foot -- mind you, Boston is a very walkable city -- we opted to use the service to travel further distances, e.g., from Boston to Cambridge and back. Let's just say I came away feeling as if Uber is the best thing since sliced bread. In case you've never used it, all you have to do is use the Uber app on your phone to indicate where you are and where you want to go. You'll be assigned to the driver nearest you, who will likely arrive in less than 5 minutes. The fare is charged to the credit card you have on file, and you can later rate the driver as well as your overall experience. Luckily, all our drivers were prompt and friendly, earning them high marks from us. I'm amazed at ho...