I like to use our Rio Karma MP3 player in the car, but it's not nearly as good as it could be. So here are some jottings on what an ideal car dock would do for the player.

• Power and charge the player, of course
• Offer various options for sending audio to the car, including a built-in quality FM transmitter, a port for a special Cassette sized interface (more below) and various cables for car stereos that have an accessory jack (as mine has for a trunk CD-changer) or plain audio inputs.
• A wireless remote control to stick on the wheel (not needed if other remote control methods can work.)
• A microphone.
• To get really fancy, an 802.11 interface to allow it to sync up with computers inside the house while in the driveway. Though strictly, this would be even better inside the player, not in the dock.

The microphone would perform several roles. One, it would detect the ambient sound level in the car, and boost the music volume as the car gets noisier. No more super-loud when you start the car either.

Secondly, it would listen for the sound of the music the player is playing. It would try to tell if it was playing, so it could detect when the stereo is turned off or switched to something else, or when the car is turned off (if the loss of power from the accessory jack doesn't already reveal this.) When the sound stops (even if this takes 5 seconds to confirm) just pause the music back in time when the sound was first detected to stop. One could then from time to time send out pulses of the forthcoming audio, and if it hears them, treat that as a resumption of play.

Generally, I'm the last person to suggest we use technology to control people's lives and what they view. However, it's also the duty of parents to help teach their children how and when to use the media. Most commonly today you see things like the V-chip, which let parents block their unskilled children from seeing shows with certain "ratings."

Thinking more about the future of mobile audio (see Tivo for Radio Entry) I start to wonder if XM and Sirius satellite radio are doomed propositions. They seem like a good idea, nationwide radio, 100 channels, many commercial-free.

But how many of the stations does any given listener actually use? I would guess most people only listen to a few of them, just as they only listen to a few on the local dial.

Recently, we picked up a Rio Karma, which is a 20gb handheld jukebox that plays MP3, WMA and Ogg Vorbis. Particularly nice things about it include the Ogg support and the fact it has Ethernet, so that any machine on our net can transfer music into it. That's about all it does with the ethernet (it also has a small web server to serve the manual and a java transfer app) but I expect it will do more later, like be a streaming media gateway when docked on the stereo, allowing control from anywhere.