Object Push Profile (OPP): This profile enables sending data (or "objects"), such as virtual business cards or contact information. Car kits that support this profile can synchronize contact lists from the paired phone.

Phone Book Access Profile (PBAP): This allows the exchange of Phone Book Objects between devices. With a cell phone and a car kit talking nicely to each other, the speakerphone can display/announce the name of the person calling you.

The last thing you want is to buy a Bluetooth headset and discover that it's a bad match. Then it ends up buried in your bag or in your glove box, unused. To avoid that scenario, keep these tips in mind as you shop around.

Factor in your environment: If you talk on your cell phone a lot in your car or on public transportation, or in other potentially noisy surroundings, look for a headset with a good reputation for noise cancellation. (This aspect does not apply to stereo headphones, as you should not wear a set of headphones, which cover both ears, while driving.)