Or, similarly, wouldn't it be cool to have a chat app that would detect people in the same geographic location traveling at the same speed. So your contacts would be the other people in the bus or train or plane that you're traveling in.
Some wise guy came up with the brilliant idea of maintaining a real-time "Top 10 Speeders" leaderboard for every single road on the entire map. Kinda like Foursquare for speeding on local roads. No matter where you were driving in the world, you could instantly see the top ten speeds of other TomTom users who drove down that same stretch of road, and put the pedal to the metal to claim or defend your own spot on the leaderboard!
That one went over like a lead balloon with the legal department.
The only thing worse would be a chat app for texting while driving above the speed limit with other Leaderboard members along the same stretch of road.
They also didn't appreciate my proposal for TomTomagotchi: a simulated personality on your PND that relentlessly begs you to drive it all around town to various interesting places it wants to visit, to improve its mood and satisfy its cravings. (Kind of like having virtual kids!) I'm sure there's a revenue model having drive through Burger Kings and car washes pay for placements.