I've used the cartridges myself, which look like tiny wax cubes, in Xerox Phaser 8560 printers. If you're unfamiliar with solid ink, they're pretty easy to use.

Xerox’s Phaser 6140/N color laser printer aims for the budget-minded SMB market with its $399 price (as of 10/6/2009). It delivers what you could reasonably expect for that cost, namely ...