Lake also makes sandals these days. They're pretty great. LXSDL is the product name.

On top of my SPD shoes I usually carry a pair of minimalist shoes for hiking purposes. They're usually lightweight and can be rolled into a small...well, roll basically.

Then again we walk around a lot on tours these days. We have two small kids for whom running around playgrounds and new towns is much more important than sitting in a trailer or in a bike seat so having comfy walking/running/jumping/climbing trees shoes is a priority.