Then, of course, there's the Internet radio Web site Slacker, which sells its portable Slacker G2 player. Slacker's portable device works by storing copies of stations from its Internet radio service on the product when you're at home, so you have plenty of fresh content on the road. (You can also store a few of your favorite tunes on there as well.)
The device allows you to mark certain songs as favorites, which will cause them to play more often, or ban them. And if you pay for the premium radio, you can even save played songs to the player to player to listen to later.
These new options can help keep MP3 players fresh, but they'd all have even more potential if they could connect to the Internet on the go. That ability, though, is where music phones continue to deliver "chin music" to the iPod and its competitors.
Ross Rubin is director of industry analysis for consumer technology at The NPD Group.