Thinking of switching to a Verizon iPhone? Well now there's an App to help you see exactly who has the (stated) best coverage in the areas that you will be using your phone. CoverMe! does a clever job of allowing you to either use your current location or an address/zip code to compare the coverage maps of AT&T, Sprint, T-Mobile & Verizon. Of course actual coverage and cellular performance isn't as simple as the carrier's stated coverage, but this App can definitely give you a good idea of who has coverage where. For example, my grandma lived in the boonies in Georgia so I keyed in her zipcode (30635) for fun and it was clear that If I was living there I'd want a Verizon phone. However, in areas like NYC all the carriers state that they have great coverage according to their maps. So in that case take it for what it's worth. These are maps not actual experience/testing.
What about 3G/4G data?
This App only shows the coverage maps for voice, not data. That would be a really nice addition in the next update. If nothing else this is a fun app to play with.