We all know that you can play MP3 files on your Clie NX series, and while the ear buds included aren't bad, did you know that you can use your NX's MP3 player functionality in your car or at home?
1. Buy a "CD to Cassette adapter". One came with my portable CD player, but you can get them separatly from places like Radio Shack and Best Buy, and they're inexpensive. This device is a cassette case with some electronics inside with a cord coming out the end. The concept is that you plug one the cord into the headphone jack of your portable CD player (or MP3 player) and then plug the cassete-end into your cassette player. The electronics inside "fools" the cassette player to think it's playing from a tape when it's actually getting its signal from the portable CD player.
The sound quality is excellent, and it's pretty portable--just wind up the cord when you are done and slip it into your glove box or pocket.
2. Buy a wireless FM transmitter. I purchased an "iRock" wireless FM transmitter from Radio Shack for about $30.00, and I am (pretty) happy with it. THis device plugs into the headphone jack and then transmits the audio over one of four selectable FM frequencies. Tune your car radio to the selected frequency, and you are hearing your MP3 music! Pretty cool!
My only complaint with this is that it introduced a bit of "hiss" into the sound stream. Also, the design of the on/off switch is, in my opinion, very poor. It's too big and doesn't take much of a tap to turn it on ot off. The implication is that this CANNOT be "pocketed" because it will most likely turn on and drain the batteries. That said, the cool thing is that unlike the wired cassette adapter, you don't have to have a cassette player to make it work, and you just have to have the device within about 10-20 feet of the receiver. This means that you could turn on your home stereo, tune it to the proper frequency, and play your MP3's from your living room chair. Again, the wireless aspect of it introduces a bit of interference, but non-the-less, it's a neat gadget.
So, both have their place, and both have their advantages and disadvantages. The point is that these are just two more ways to extend the usefulness of the Clie NX PDA.