If you spend a lot of time listening to music on a portable audio player, and also spend a fair amount of time on the cellphone, you've probably dealt with the headset swap. You know, it's when you're in the middle of rocking out and your phone vibrates (after all, you're not going to hear it ring). You either frantically switch headsets or yank your headset off, just in time to discover that the call's rolled over to voicemail already (either that, or it's someone you really don't want to speak to). You could do what we do and just let the voicemail pick up anyhow, or you could pick up the new Plantronics MX-100-s combo. As you may have guessed by now, it's a single set of earbuds that works both as a cellphone headset and stereo phones for a portable audio player. Plantronics is pitching this as an iPod accessory — it comes in the obligatory white plastic, can be bought at Apple stores, and presumably sports one of those snazzy new "Made For iPod" stickers. Needless to say, it should work with any audio player. While we think this is a step in the right direction, it's still a tangle of wires, especially if you're used to keeping your phone and audio player in separate pockets. The dual jacks on this thing mean they're joined at the hip — your hip, if that's where you stash your gear. What we really want is a version of this that does Bluetooth. But somehow we don't expect to find that for $40, which is what this goes for.