The Sony Vaio VN-CX1 USB mouse and Internet telephone is a mouse that also makes and receives Skype Voice over IP (VoIP) calls.

Dubbed the Ringing Rodent in the PCW office, the product is as bizarre as it sounds, because it is a mouse and then a phone.

Ergonomically, it's not that comfortable to use for either function. As a mouse its too small to comfortably use for the bulk of the day - we found we had to arch our hand to use it, rather than our hand following the contours of the type of mouse you'd typically use with a computer.

Its clamshell design folds open to use it as a phone. The sound quality is clear, if a little tinny, and it's again a little uncomfortable to hold while talking.

You'll need to hold conversations close to your PC and, as ever with Skype, your computer must be on for it to work. When operating as a phone, the mouse functions are disabled, so you won't be able to operate your PC.

It also has a hands-free function. To get this to work you need to press the buttons on its hinge so that the clamshell flips openly slightly. It was easy enough to hold a conversation, but you will look ready for the funny farm as you speak to your mouse.

We couldn't help thinking some aspects of this device just haven't been thought through.

For instance, if Skype's already loaded, opening the clamshell brings up your contacts list as the main window. Except, because the mouse element has been disabled, you can't scroll through to the name you want to ring, so what's the point? Nor will pressing any buttons ring the contact name that is highlighted.

As a novelty device, the VN-CX1 works fine - although you might get fed up with it for everyday use. But at £55, it's an expensive novelty, especially when there are so many Dect handsets for Skype selling in a similar price band, or far cheaper USB headsets and handsets.