Sony has entered the VoIP market with a new mouse that promises to double up as a clamshell mouse designed for laptops when you aren't whizzing it around the screen.

The Vaio VN-CX1, as it will be known, is Sony's attempt to tap into the ever burgeoning VoIP market.

However a design flaw of being unable to use the mouse and the VoIP handset at the same time means it will only be useful for laptop users.

Desktop users however will have to revert to using the phone's speaker or resisting the temptation to do any work while they are making the call.

Callers are notified that a call is coming in either by the discrete LED on top of the mouse or a ringtone. Users can then press a button on the mouse instantly turning it into a phone.

During a call, the centre scroll wheel acts as a volume control and can also mute the phone.

Connected via USB, the device works on any Windows PC, however the user will have to install specific drivers.

On the mouse front, the optical mouse offers an 800dpi and weighs 67g making it an ideal travel mouse for business users.

The VN-CX1 is available in three colours; black, silver and blue and will cost £55.