Canon EF-S 17-85mm f/4-5.6 IS USM Lens

This is one of the optional kit lenses for the 20D/30D & 40D cameras.
As a non 'L' lens it is very good, and is excellent value (especially if bought as part of a kit with a body).
Until the end of June 2008, Canon have a £40 rebate on this lens (you must provide the bar-code, and receipt) so double check with your retailer.

Compared to the 18-55mm that many of the range come with, this is massive, but it's a reasonable size and weight for what it does.
The optical image stabilisation works well, and it covers a good range of focal lengths (27mm to 136mm equivalent field of view).
The front element doesn't rotate during focussing or zooming, and the recommended hood (the EW-73B) is a petal type that can be stored back to front on the lens.

Summary: While optically not quite as good as the 17-40mm F4L or 24-105mm F4 L lenses, it is a fraction of the price (and weight) of either.