The Indiana State Library has a new resource, Fire Insurance Maps Online (FIMo).
It contains Sanborn, Baist, and other insurance maps for over 300 Indiana cities and towns covering the mid-1880s to mid-1960s. The best feature is that you can put in a modern address or geographic coordinates and it will show you what maps are available for that location and allow you to overlay the historic map over modern Google imagery. You can then download images to a flash drive or print them.
This subscription resource is only available on location, but the trip to the Indiana State Library in Indianapolis is worth the trip!