Computer chips may be able to crunch their way through millions of calculations per second but meeting one is a not particularly exhilarating experience. It is, I am sure you will agree, difficult to get worked up about a flake of silicon a centimetre across.

That is why I was delighted to learn recently that there is another reason why we should admire microprocessors. Unbeknown to most of us, and to their employers, chip designers have been signing their creations. The microscopic signatures range from real signatures of the designers themselves, to full-blown artworks. The clandestine practice was uncovered by Michael Davidson, a research scientist in Florida who, a decade ago, started photographing the delicate circuitry on silicon chips. His first discovery was an etching of Where's Waldo (known in the UK as Where's Wally).

The tradition began innocently enough about 20 years ago, with designers simply initialling the chips they worked on. It was the top of a slippery slope - it quickly became a mildly subversive activity, with the themes getting more playful. More modern etchings include detailed pictures of cartoon characters, animals and even landscapes. Davidson has compiled his favourite photomicrographs (photographs taken through a microscope) and put them on the Internet (http://www.microscopy.fsu.edu).

The site, called Silicon Zoo, is a feast of ingenuity - various chips feature a miniature herd of buffalo, a giant (1.5 mm) crayon, Godzilla, a T-Rex strumming a guitar and a likeness of Groucho Marx.

One chip has more than 100 different bits of graffiti on its surface; another chip features a minuscule warranty disclaimer (in jest, we hope).

The site offers a tutorial into how the doodles, scratched on to the upper layers of a chip, are created.

Unfortunately, the practice is now banned by many companies, because, they say, the designs can confuse the checking procedures.