Even though Google has a stronghold on search, there are many map services out there that rival the advertising giant's effort to catelogue the entire world. Bing provides a very similar service to Google Maps, and if you want to compare the two of them side-by-side, DualMaps is definitely the way to go. This web app goes above and beyond the call of duty for map comparisons.
The site might seem a little complicated for novices, but that shouldn't scare them away from trying it. If you know the exact coordinates of the map you want to generate, fantastic. If not, you can click and drag a typical Google Map to show DualMaps where you want to make your map. The site also has a host of popular topics for you to base your map on, like restaurants and hotels.
The funtionality of DualMaps is superb, with a display that literally takes both sites' results and puts them side-by-side for comparison. Each map has the full functionality that it would have on its own respective site, making DualMaps a fair judge of both. The site even gives you an embed code that you can use on your own site or blog to put the comparitive maps on. It's extremely useful in the sense that both sites feature separate content, and provide emphasis on different businesses.
You might not realize what the difference is between these two map services, but after a quick run with DualMaps, you will. While Google is the most popular service, Bing can very often pick up sites and businesses that aren't as featured in Google, which is a help. Try it out for yourself, and let us know what you think in the comments.