Whoa! He used "impetus!" I had to look that one up!
Johnoz - need a cheap ultrastable zoom lens? Just wait until after xmas when the 1st semester of classes that require photography equipment are all done. Then visit the local camera stores (Henry's, Vistek etc) for wicked used lenses.
Canon has zoom lenses with IS (Image Stabilizing) that actually steadies the image from handshake. Awesome feature.