Two of my favourite camera bag manufacturers start with L: Lightware and Lowepro. At PMA 2003, the latter was showing off the latest addition to its waterproof camera backpack line, the DryZone 100.
Essentially a smaller version of the DryZone 200, the DryZone 100 features a waterproof rubber-covered nylon shell around a padded, multi-compartment backpack. The waterproof shells seals tight with a drysuit-style TIZIP zipper; the inner enclosure is a standard zipper. Both models come with a well-designed and comfortable backpack harness (the DryZone 200, in fact, is the most easy-wearing camera equipment backpack I own).
If your photography takes you anywhere near the water, either the DryZone 200, or its smaller sibling, the new DryZone 100, are worth checking out (Lowepro's web site is not yet updated with info on the DryZone 100).