Microsoft's search engine Bing also has a satellite map site called Bing Maps (
http://www.bing.com/maps/). I think it retrieves the map images from the same satellite that source Google Maps, although Bing Maps does not let you zoom in as far plus images look less high quality than Google Maps satellite images. However, Bing Maps has a feature that Google Maps doesn't have, that is a bird's eye view taken from a aircraft instead of having to rely on distant satellite maps. Both mapping web applications seem to have their own advantages and disadvantages, with Bing Maps having issues with searching street names, inaccurate property locations (i.e. street numbers correspond to the wrong house on the map) and no Street View photos, while Google Maps have a more developed and matured product that only lacks an aerial bird's eye view.