Think of these pretty portable players as the lovechildren of TiVo, satellite radio and the iPod. They allow you to record your favorite crystal-clear satellite programming TiVo-style and then listen to it later on, wherever you are. Although these wearable units are not themselves satellite receivers-they have to be docked to receive and record content-the XM Samsung neXus and Sirius S50 have two key advantages over their antenna-outfitted relatives: They´re half the size, and you can upload your MP3 and WMA files and mix them into your satellite-radio playlists.

Maybe you first tune in the station driving past some lobster-roll shack just outside Bangor, Maine. You know the music isn't coming from the local FM radio tower a few miles away. Instead, it's being digitally compressed and uplinked from a massive command center in Washington, D.C., bouncing off a pair of Boeing satellites in geostationary orbit high above the equator, and finding its way to a sleek little shark-fin antenna mounted on the trunk. The technology is at best a compelling afterthought, because after the fourth or fifth song, you realize the music speaks to you.