route-me – Google Code (via /.) is a mapping library for the iPhone that uses OpenStreetMap instead of Microsoft or Google’s mapping engines. It’s available under a BSD license and has some reasonable “how to embed” information on the wiki pages of the Google Code site to get you rolling.
I knew about OpenStreetMap from OSCON last year (or maybe even the year before) – but I had no idea that someone had put together this library. The terms of service for Google Maps are actually somewhat restrictive, Microsoft is quite a bit better, but this really tops them all. The mapping is also incredibly good. The united states have been pretty lucky that the information is technically “free”, even if finding it in published forms that is useful can be tricky. Other countries are FAR less open. The UK, for example has incredible ordinance survey maps, but they aren’t considered “public information” there.
Anyway, if you’re considering a mapping component to your iphone application consider checking this out.