Hold button
The hold button feature is absolutely critical for being able to reliably operate the audio player without having to worry about accidentally turning on the device and running down the power. There are actually two hold buttons, one on the left side of the device and one on the audio player remote as well. You can use the hold button on the side of the device to prevent yourself from accidentally turning it on. With the hold button on, though, the remote control can operate the audio capabilities of the device. This allows you to run the audio player without the screen being on, which is essential to being able to conserve the device's power. And, since an LED indicates whether or not the Memory Stick is being accessed, you can also tell by sight whether the audio player is running or not.

Jog-dial
The CLIE includes an extremely useful jog-dial that aids you in finding important information quickly, while using only one hand. Once you get used to using it, it'll be very difficult to go back to a Palm OS device that doesn't have it.

Back button
The back button is very useful and complements the jog-dial feature perfectly. Note, however, that the back button isn't included on the grayscale PEG-S320 model. But, then again, that model only costs $199.

Expandability
The Memory Stick slot allows you to instantly add up to 128MB of storage, and it's extremely simple to swap out different Memory Sticks. Buying an additional memory card is essential if you really want to listen to audio on the device, since the 8MB card the device comes with will only tease you with two or three songs. You'll need at least a 64MB Memory Stick, but if you really want to maximize your choice and if you're not too concerned about price, go ahead and get the 128MB Memory Stick.

When I bought my Sony CLIE, the 128MB Memory Stick had just become available. In fact, the only store where I could find it was the Sony Style store at the Metreon in San Francisco. At the time, the 128MB Memory Stick cost $239. I went back and forth about spending so much on something that looks like a purple stick of gum, but I decided that I had come this far and might as well just go all the way. Recently, however, I've seen the price drop to $149, both on Amazon.com and at Fry's Electronics. Yes, I have thought about the fact that if I would have waited three months I would have saved $90, but it's a small price to pay to be an early adopter.

The WOW factor
One of the ways I judge whether or not a new technology is compelling is the reaction I get when I show it to a cross-section of users, from non-technical people to uber-geeks. The reaction I got when showing people the Sony CLIE was always extremely positive and enthusiastic. I even came up with a set presentation I'd give to people, guiding them through all the features on the device, including the audio player and how fantastic pictures of my kids looked on the screen. I really knew the device was a winner, however, when I showed it to my very non-technical in-laws and they were blown away by all it could do.