Lake also makes a line of shoes they say are for bicycling "adventures," including hiking and climbing with the bike. They would work wonderfully for your purposes, I should think. Take a look at the MX 225 ($130), which has a grippy Vibram sole, water-resistant leather, a tough toe cap to protect your extremities, and a scree collar so loose rock and dust can't get down into the shoes. And of course they'll adapt to most any clipless pedal system.
Diadora's Santa Cruz ($99; www.diadora.com) is another shoe that combines biking functionality with good adaptability for walking and scrambling. Plus, they look pretty good, so if you stop at a restaurant or bar, people won't think you're a complete dork. Cannondale's MC610 ($80; www.cannondale.com) is another all-purpose shoe that looks pretty good and works well on or off the bike.
Still, I like the Lakes. And I wish more shoe makers took seriously the idea that people want a shoe that's good for both hiking and biking. I've suggested to Montrail that they take one of their very fine trail runners and add a bike cleat component. Alas, to no avail.
Check out the 2005 Gear of the Year winners in Outside's 2005 Buyer's Guide , then get yourself a copy of the issue, on newsstands now!