I'm an independent software developer that's spent the last few months creating software for viewing and searching map data. The software has some navigation functionality as well (mapping, directions,etc). The eventual goal is to sell it in mobile app markets. I use OpenStreetMap as my data source.
I'm concerned about liability for erroneous map data / routing instructions, etc that might result when someone uses the application. There are a lot of stories on the internet where someone gets into an accident or gets stuck or gets lost because of their GPS unit/Google Maps/mapping app... I myself have come across incorrect map data as well in a GPS unit I have in my car.
While I try to make my own software as bug free as possible, no software is truly bug free. And moving beyond what I can control, OpenStreetMap data (and street map data in general) is prone to errors as well.
What steps can I take to clearly inform the user that results from the software aren't always perfect, and to minimize my liability?