This is a brain exercise noted by Edward de Bono, and implemented by Kevan Davis - there is (or rather used to be) a full explanation at De Bono's web site, archived here.

The aim is to think of a category that four of these words fit into, and the other four do not. Drag them around the screen, into two groups - it should be possible to come up with something.

To play competitively or comparatively through a messenger system, with everyone using the same words; agree on a seed number with your opponents and have everyone enter it in the box below, before pressing return.
To get another eight random words, just reload this page.
wind turbine
pencil sharpener