From old-school B-movies to laser-generated holograms, 3-D images have long been a source of fascination. And why not? It would be a shame to lose that precious third dimension.

Alas, creating and manipulating realistic 3-D images has not always been easy. But advances in digital technology are enabling everyone from laboratory researchers to Hollywood filmmakers to expand the range of 3-D imagery available to us; witness the great scans released last week showing two 300-million-year-old proto-spiders (see the next slide).

Some 3-D imaging applications are helping to save lives; others are purely frivolous. Some are quite sophisticated; others, surprisingly simple. None will leave you flat.