In which I set the tone.

On my hard disk lies a text file, named simply "003", undisturbed since 12 July 2008. Its contents are as follows:

cartesian donuts

The 1913 Webster says a Cartesian oval is a curve such that, for any point of the curve mr + m'r' = c, where r and r' are the distances of the point from the two foci and m, m' and c are constant. So there you are.

Alternatively it could be a donut that exists only because it thinks that it exists, although that raises the obvious question -- how does it know it's a donut and not a coffee cup...?