There may already be a thread like this, but I couldn't find one. So what's an app (whether it's a web 2.0 one, an official Apple widget, or whatever) that you hope to see developed for the iPhone? For me, as a New Yorker, I would love to see something like Google Maps but done specifically for NYC's subway/bus routes (something better than the official MTA maps which are never quite detailed enough), showing the best way to get from one destination to another after some input from the user -- with live updates of service changes/advisories. Ok, I know it's simple... but it's the first thing I came up with. I'm sure I'll think of dozens more. So what's YOUR dream iPhone app?