I've been carting my digital music collection around in my trusty old Creative Nomad Zen 20GB hard drive player for more than a year now, and while I've really enjoyed it, the not-so-little guy is starting to show his age.

Newer players are thinner and lighter. They come with replaceable batteries. They use USB 2.0 to fill their compact hard drives, which store twice as much data.

I want one! At least I think I do. But I've looked at lots of them over the past year, and they've all seemed fatally flawed in one way or another.

None, for example, has an on-the-go playlist engine that matches the Nomad's. I thought the new generation of Creative players might be the ticket, but the 60GB Nomad Zen Xtra that I just test drove isn't doing it for me either. Its controls are spongy, and the player isn't appreciably smaller than the older models.

That's the way it is with digital music. Everybody can see what you'd need for the perfect music store or portable player, but nobody feels like building it. So begins my attempt to design the perfect portable player, in which I'll highlight the best features of a number of MP3 players and dream wistfully of a future in which a company will be kind enough to build one and sell it to me.

Controls

Every hard-drive MP3 player needs navigation and selection controls to let you move through your media library and jump around playlists. Ideally, you'd also be able to navigate lists and select menu choices using one hand, without looking at the player. That's the problem with the Nomad Zen Xtra's controls: The jog dial that's used to scroll through tracks and select menu choices is so dodgy that I couldn't tell what I'd done unless I was looking at the player's LCD. Some tactile or audio feedback as you move through menu choices would help.

Apple's standard-sized IPod is where it's at in the control department. Like many manufacturers, Apple figured out that some kind of circular device is the best solution for navigation. The IPod's control lets you move through a list very simply, emitting a soft click through your headphones as you pass each menu item. What's more, the wheel lets you go as far as you want through a list in one continuous motion. You can't do that with a scroll wheel--you have to keep picking your thumb up again and resetting it at the top of the control, which gets annoying in longer lists.

I'm surprised more companies haven't copied the IPod control wheel; it's far and away the best design out there. But I'd add a few side-mounted buttons to take advantage of natural hand position when gripping the player. There's no reason to take your thumb away from the control wheel to select a song or make a menu choice when your fingers are wrapped around the player anyway.

Interface

I'll tell you a little secret: I don't like playlists very much. I know, I know, that's the title of the column; but for the most part, I can't be bothered to create them. And I'm certainly not going to build one on my PC every time I want to play a different mix of tracks on my portable player.

For me, the power of digital music stems from the fact that I can keep my entire music collection in one place, instantly accessible at my every whim. If a chord change in a Clash song reminds me of an Elvis Costello track I haven't heard in a while, I ought to be able to add that song to the list of tunes I'm playing without any premeditation.

That's where the Nomad players excel. Find anything in your music library and you're given the option to add it to a "Now Playing" (on the older Zen players) or "Selected Music" (on the newer models) list. Find a lineup you like, and you can save it as a playlist without needing a computer.

The great thing is the way the list becomes a useful subset of your collection for as long as you want to keep it around. Albums, artists, and playlists are all recognized as objects, so you can view them expanded to show every song or collapsed for easier navigation.

Every so often, I'd dump ten albums, a couple artists, and a few favorite tracks into the Zen's Now Playing list and spend the next couple weeks bouncing around that list, programming my morning and evening commutes with ease. It revolutionized the way I listen to music. If there's another player out there that does the job as well, I haven't seen it.

Features

Number one on my list of necessary features beyond the interface is wide-ranging codec support. The ideal player would support MP3, WMA, AAC, OggVorbis, and FLAC (a lossless compression format in which I'd store all my music if I had enough space). I haven't seen any player that supports that whole list, but IRiver's IHP series of hard drive players probably comes the closest. Rio's Karma hard drive players pack some good codec support as well.

USB mass-storage support is next on my list. MP3 players supporting this standard (IRiver scores again here) automatically show up as drives in Windows Explorer, which means you don't need a separate app to move data files to the player for temporary storage. USB mass storage also helps with cross-platform support, as both Linux and Mac OS X recognize the standard.

On top of that, I'll take support for as many digital music stores as possible, provided the digital rights management schemes don't interfere with the MP3s I've ripped from CDs I own.

Finally, size: A 40GB player can house a collection of about 500 CDs encoded at high bit rates with room to spare. That's what I want, and for no more than $400. In terms of physical size, new players shouldn't start off any larger than the current standard-sized IPod. Some of the prototypes I saw at the Consumer Electronics Show this year packed 40GB into a package no larger than a stack of credit cards. And don't move the display and controls to an in-line remote to get the job done.

The rest is window dressing. A replaceable battery, like that of the Nomad Zen Xtra, is a nice touch because it saves you from worrying about what to do if and when the rechargeable battery cell starts wearing out.

Integration with a good media management application is another bonus. I'd love to see other players supported under Apple ITunes, but since we know that won't happen anytime soon, I'll settle for a well-written Nullsoft Winamp plug-in.

So here's my perfect MP3 player: Give me the IPod's circular control wheel, some side-mounted selection buttons, the playlists interface on the Nomad, the codec and standards support of IRiver's hard drive players, and the stack-of-credit-cards size of some of the new 40GB players I saw at CES--at a price of no more than $400. Is that too much to ask?

Quick Hits

Critical Update: If you've got RealNetworks' RealPlayer installed on your PC, don't ignore the latest automated update trigger. This patch fixes three recently discovered vulnerabilities that could allow an attacker to take control of your computer.

In Heavy Rotation

A Great Single You Can Download: Though I missed the group's recent San Francisco show, I'm still stuck on The Shins' three-minute pop masterpiece "So Says I." The latest album, Chutes Too Narrow is at most of the digital music stores. It's well worth checking out.

And One You Can't: Lazy Lester sounds like the best drunken street musician you've ever heard, only better. I caught his version of "Blues Stop Knockin'" on one of the music-only cable stations at a friend's house one night. It's been bringing a smile to my face for the past month.

Eric Dahl spends too much money on CDs. To comment or ask a question, send him an e-mail.