What you should buy

Three basic types of hands-free devices are acceptable under the law.

Simplest is an earpiece with clip-on microphone that plugs into the mobile. To answer and end a call requires pressing a button on the wire. Similarly you can use a cordless Bluetooth earpiece if your phone is compatible.

Alternatively, buy a fully-fitted kit with speaker and microphone wired into the car. This can be adapted to use the car's speakers. Thirdly, there are devices which plug into the cigarette lighter which can be moved from car to car.

Here are the five best buys:

1 Jabra BT200, £49.99. Best-selling Bluetooth headset. Make calls through voice-activation or button. Three hours of talk time, 240 hours' standby time.

2 Plantronics M3000 Bluetooth Headset, £79.99. As above but with eight hours' talk time, 200 hours standby.

3 Pama Clip'n'Go from Carphone Warehouse, £19.99. Uses a clip which goes over mobile phone to amplify through separate speaker. Plugs into cigarette lighter, includes in-car cradle.

4 Pama Professional Carkit, Carphone Warehouse, £59.99 or £99.99 with installation. Fully-fitted hands-free kit. Charges phone while in "cradle". When it rings the radio automatically mutes and caller's voice comes through car's speakers.

5 Vodafone in-car holder. £4.99.

Basic cradle for mobile. Has sticky pad that fixes to dashboard. Needs to be used with headset.