I'm trying to make my Droid my all-in-one in-car device, but have run into problems with the inputs and outputs.
Is if there is any application (or ability to create one) that would assign the headphone jack, internal speaker/mic and bluetooth to specific applications so that they can be used simultaneously as desired. In my case, I'd like the headphone jack to play a podcast (via cassette adapter), the GPS to listen to the internal microphone and speak through the internal speaker, and the phone to work through a bluetooth headset, all at the same time.
Others might want to assign the same devices in a different way. It would seem like some kind of operating system tool or application would be necessary to get full multitasking flexibility out of Android devices.
In the old days, plugging into the headphone jack would electrically disconnect internal speakers and mics. Don't know if it works like that anymore.