I was out "running" (more like plodding, but whatever) yesterday and startled a bird in the sagebrush. I wasn't sure what it was, and the thought of slogging through all 810 listed species, looking for a match seemed daunting. That made me think of how the overall list could be pared down in situations like this, and I thought, "Eureka!".
The iPhone has geolocation abilities. It also knows the date. The Peterson Field guide has range maps. Bingo! Put the two together and you can have a filter that essentially says "Show me only the birds possible in my current area, at my current time of year, based on their range maps."
I think that would be really cool. Then, when I have opportunity to be across the country, I can do the same, and see a display of only the birds in that area, during that season. I think that would make identification a bit easier. What say you?