How can I turn my Optimus S into a media player only?

[Sumpm]

I have a Optimus S that I no longer really have a use for, so I thought I'd just turn it into a media player, similar to an iPod Touch.

What ROM(s) is available for me to do this, if any? I don't want it to keep trying to contact Sprint or update the ID.

It'd be nice to be able to just leave it in my car, loaded with MP3s and not have to use my main phone for that.

 

[epidenimus]

CM7 is probably your best bet, since it is lightweight and you can turn the 3G off and toggle the wifi as you please. It is not stock-based, so you don't have to worry about OTA updates or anything. The Tablet Tweaks even allow you to disable the lockscreen completely, Car Home is installed out-of-the-box, and there is great widget support (for Music or other media player).