Adventure travelers on extended trips have a luggage problem. If you're going to be spending a couple of months in the bush, chances are that you're going to take a least a little time to go on a trek, climb a mountain, sleep in a tent, or otherwise explore the outdoors – and that takes gear. More specifically, it takes trail shoes.
Perhaps no piece of equipment is as important to an adventure traveler as a well-fitting pair of hiking boots or trail shoes. If your feet are miserable, you are miserable; it's just that simple. You'll want comfortable well-fitted shoes you can hike or walk in day in and day out, shoes rugged enough to handle whatever kind of activities you plan. You need shoes that look appropriate in towns and cities, and can be worn on tours, on safaris, and on long bus rides. Traditional hiking boots are fine on the trail, but off the trail, they fail the comfort and usability test. They are too big, too hot, too stiff, and too heavy.
So first things first: Forget about full-fledged old-style hiking boots. Unless you are going on a serious multi-day trek that will take you above the snowline (Climbing Aconcagua, Kilimanjaro, or the high passes of Nepal), you don't need them. And even then, you can probably get by with lightweight fabric hiking boots.
For most trekkers, especially if you are traveling inn-to-inn or hut-to-hut, or if pack animals or porters are carrying your equipment and food, hiking boots are simply not necessary.
Hiking Shoes
Hiking shoes (not boots) are the first and obvious answer. Hiking shoes (also called trekking or trail shoes) are different than running shoes in that they have more support around the entire foot and under the arch. They have a stiffer sole, as well, and better sole traction for hiking on slippery surfaces . You can increase the amount of support (especially under the arch) by using insoles such as Superfeet, but be sure to try the shoe on with the insole to be sure everything fits. Most of the major outdoor footwear manufacturers – Reebok, Lowa, Merrill, Keene, Teva, and many others – make trail shoes.
Water Shoes
Pioneered by Teva, water shoes or sandals, are designed to go in and out of water. Ideal for river-based trips, such as kayaking, or beach hikes where you may have to wade in and out of tidal pools, they are remarkably hardy and can even be used for hiking (although probably not a long trek).
If hiking for a few miles in water shoes, you might want to wear them with socks to prevent little bits and pieces of pebbles and dirt from creeping in and causing blisters. For extended hikes, the lack of foot support, particularly in the arches, can be a problem. Open toes are also a problem, especially in rocky terrain. These wouldn't be a good choice for riding a horse, nor for extensive hiking, because they leave the foot too vulnerable. But if you have to hike a few miles in them, and the terrain isn't too rough, you'll get by.
Semi-Open or Ventilated Trail Shoes
Hybrid sandal-shoes shoes such as those made by Keen are a great compromise: They cover the whole foot, including the toes, but some of the shoe is actually open, so they have the breathability of a sandal. Merrill's so-called "Ventilators" have a mesh that lets air in and out. These shoes offer full foot protection, yet are ventilated enough that you can wear them without socks. They're made of materials that can either handle getting wet, or will dry quickly, so it's no big deal to stomp across a river in them.
Some brands are stiffer than others, and have more arch support. (Insoles can be worn with some of these shoes, as well.) If you will be walking long distances, the stiffer styles also offer more support around the foot. Also look at the soles to consider traction: If you expect to be hiking up and down muddy or slippery slopes, be sure the sole looks grabby enough to do the job.
Hiking shoes, water shoes, and hybrid trail shoes offer some huge advantages: They weigh much less than traditional hiking boots (sometimes under a pound for the pair, as opposed to three or four pounds for traditional boots). They don't need to be broken in and are unlikely to cause blisters. They are comfortable to wear in everyday life, in towns and on tours. And they don't take up precious luggage space and weight.