There was a new law I think passed last year (2004) that went into effect on Jan. 1, 2005 in the State of California on what type of "video displays" can be visible to driver.

On the California Driver Handbook – Laws and Rules of the Road says:

Do not drive a vehicle equipped with a video monitor if the monitor is visible to the driver and displays anything other than vehicle  information or global mapping displays.

I need to do some digging and find the actual reference.  From the above text, I think even looking at my iRiver MP3 players screen could be consider a violation?

[UPDATE: Political cartoonist David Branch has his take on the Video iPod.]