Mirror your iphone display to an extneral display
There are several people working on this. It is my understanding that currently the touch features get disabled when you use the output mode. Even with touch disabled, this could be a great step in the right direction to getting turn by turn navigation working in cars with built in video screens or for people that just want to mirror the content of their iphone on their car screen.
Here is one of the links:
Has anyone done this yet?