Here's a link to my comment about the excellent post by Mike Elgan on the untapped potential of GPS on the iPhone: I just don't understand why someone has not created an IRS-friendly mileage logging application yet. And the potential for using GPS to enhance the capabilities seems obvious to me. Hey developers, get cracking! You're free to use my ideas as long as you give me a break on price. I'd be happy to beta test for you when I get my 3G in July.