Thats a good challenge, but there are shoes out there that will do the job.
For example, you might like the New Balance 628 Country Walker ($80). These are walking shoes built with running-shoe technology. But they have brown nubuck leather uppers with nylon inserts for breathability. They look pretty much like normal casual shoes. Add a pair of khakis and a polo shirt, and you could fit in anywhere.
Another good shoe for rugged walking while maintaining panache is the Timberland Barentsburg Plain Toe Oxford ($100). These have tough leather uppers that have the look and cut of dress shoes, sturdy soles, and a lining to keep out rain. Very nice.
If your travels take you where its fairly cold and wet, then get a pair of Clarks Muckers ($110). These are mid-height shoes for a little more protection, but they will still fit under trouser cuffs. Plus, they have a waterproof lining, leather uppers, and grippy soles. They are good-looking, too.
To any of these, add a pair of SmartWool Ragster socks ($20) for a look thats not too casual but is comfortable for all day on your feet.
The 2008-09 Winter Outside Buyers Guide is on newsstands now. Look for it online soon so you can get prepped for gift-giving seasoneven if everything you pick is for yourself!