In Tampa, we have a lot of out-of-state buyers that typically don't have a lot of time to visit homes when they come to town. By using online maps to find your new home you see the terrain, photos of the area, satellite images, traffic and all sorts of other information without even starting the car.
Google Map has a great feature called street view. With street view it's like you're driving through the neighborhood yourself. You can take a virtual drive to see how well the other homes are kept up and the curb appeal of the home that you're interested in. The photos for street view are taken from a special rotating camera placed on top of a car and driven through the area.
Bing's map has a couple features that I really like. The first is the bird's eye view which is made of aerial photos taken from four angles. The photos which make up the bird's eye view are typically taken at different times of the year which allows you to get an idea of how the home looks like during different seasons. The other great feature with Bing is their use of labels. You can have different services, such as hospitals, restaurants and apartments, labeled on the map. This is a great option if you need your next home to be close to a hospital or library.
Using online maps to look at the homes suggested by a local REALTOR will save you time and gas.