This article originally appeared in Light Plane Maintenance, Mar. 2005.Elbow grease, grease the skids, greasy kid's stuff; grease makes the world go 'round -- literally. The earliest forms of grease were various and sundry animal extrusions and leftovers. Today still, numerous organically based greases give excellent service -- although their origins are more from lithium and calcium than bears. Synthetics have largely replaced organics in many markets, with wide temperature-stability being their biggest advantage.