The devices connect through a process called pairing. To start pairing between a headset and a phone, you use your Bluetooth phone's interface, making sure that the headset is turned on and in pairing mode. The phone then searches for and locates the headset. To establish a connection, depending on the version of Bluetooth that your phone and headset support, you may need to enter a PIN on your phone's keypad; afterward, your phone will recognize the headset. And, you hope, the devices will talk--nicely--to each other. The process is identical when you pair your phone with a speakerphone. (For more details about Bluetooth specifications, see ".")

Headsets: You'll encounter a huge variety of Bluetooth headsets on the market. A monaural (or mono) unit has a single earpiece and a design that puts the microphone close to your mouth. Stereo headsets or headphones come with two earpieces. Though they bring you stereo sound and let you listen to your tunes as well as make calls, their microphones typically sit much farther away from your mouth.

You can find models from traditional headset makers (such as GN Netcom--the name behind the products--and ), cell phone manufacturers (such as and ), and Bluetooth-only companies (such as ). At the low end, Bluetooth mono headsets start at about $15; at the high end, you can expect to pay at least $100. Stereo headphones can be $50 to $200, sometimes more.

As far as headset design and style go, take your pick: over-the-ear or earbud (some do both); silver, gold, candy-colored, black, or gray; sleek or boring; bulky or discreet; long or short; lightweight or superlight. Over-the-ear (aka earhook) headsets can have wide, loopy hooks or thin, narrow ones; they can be plastic, rubberized metal, or leather, too. Some headsets have earbuds that are completely round, while other buds have tips that protrude. Some stereo headsets have earpads that sit on the outside of your ears and are connected either by a neckband or a cord.