For the techies out there, it's a SiPix StyleCam Blink, and it's about two inches square and a half-inch thick -- 5x5x1.5 cm.
However, the USB connection is not going to work on his computer (NT Workstation 4.0).
This weekend, I've promised him, I'll upgrade it to Windows 2000.
However, it works fine on my laptop, which is Windows 2000 already.
He bought it here for forty quid -- it is this page which includes the "tight jeans" reference, where they have spelt "unnoticable" thus, wrongly.