I recently wrote up a review of the Plantronics .audio 910 Bluetooth Headset, a great way to chat on Skype and on your mobile phone wirelessly. But what if you already have a bluetooth headset? You can probably still use it with Skype. Read on.

1. Make sure bluetooth works on your PC.

If you have a Mac, Sony or HP, you may already have Bluetooth installed, otherwise you'll probably need a USB adapter. Be sure to install the drivers that came with the adapter (or check the manufacturer’s site or updated ones). The bluetooth stack built into Windows XP doesn't support the headset profile (I’m not sure about Vista), so you'll need to use the provided drivers (often made by a company called Widcomm).

2. Pair your headset with your computer.

This depends on both the bluetooth driver and the headset. On your computer, if you right click on the bluetooth icon in the system tray, you should have an option like 'Add device' or 'Bluetooth Configuration Wizard.' It will probably give you the option to choose the device you want to use or choose the service you want to use. You should be prompted to have your computer search for the new device. At that point put your headset into pairing mode--you'll have to check your manual or online for how to do this, it's generally holding down some combination of buttons to make the light change color / flash differently. When the computer recognizes the headset in pairing mode, it may ask you to type in a passkey. This is a four digit number and again, you may have to check your manual--it'll be the same as it was to pair the headset with your phone, and is generally 0000 or 1234.

3. Make the headset your Skype audio device.

Once you're paired, the white bluetooth logo in the system tray will change color to green. The bluetooth headset should then be one of the devices you can choose in the Sound and Audio devices in Control Panel and in Skype. in the skype client select Tools -> Options -> Sound Devices, and choose the “Bluetooth Audio” for both audio in and audio out.

4. Skype away.

Before you make any calls you might want to call the Skype Testing Service (echo123) to confirm your audio is working properly, and adjust your volumes if necessary (you'll be able to control the volume within the Skype client and probably on your headset as well).

These are meant to be general instructions--you can see other peoples' attempts here and here. When you’re doing this, keep in mind that when you're paired and the bluetooth icon is green, your bluetooth headset will be drawing power like you're talking whether you're talking or not. You can unpair it manually when you're not talking, but if you receive a call you won’t have much time to pair it back before answering. The .audio 910 headset’s software recognizes when Skype calls start and stop and appropriately puts the headset in standby mode, thereby conserving battery life. But if you don’t want to shell out for a new headset when you have a perfectly good one, teaching it to work with Skype is a cool new trick.