I've lived in Austin for quite a while and knew all about the bats, although I always felt like I hadn't really seen them at their best. So, I decided to book a spot for the Lone Star Riverboats. You get on this boat, and they take you for a ride up and down Town Lake, giving you a tour guide of things by the lake.
Then, you sort of park on a spot and see the bats come out from under the bridge. There's nothing like it. You get to see, smell and feel the bats at their glory. It's a great activity if you have out of town guests coming to Austin.