The easiest and least expensive form of exercise is walking. It's a great activity for a beginner because there isn't any high-tech gear to buy, just throw on some comfortable clothes and shoes and you can begin.
I started my weight loss program by walking. I gained access to a treadmill and eventually joined a gym for access to other machines, weights and water aerobics.
I still prefer to walk outside though. I've found that I enjoy hiking. Geocaching drew me in, but I found that I feel empowered physically and emotionally from the activity. I never follow the same path twice, my area is filled with beautiful parks and various trails I didn't need to buy any gear to get started.
I like the sense of adventure hiking gives me. Each hike brings a new challenge and a different territory to explore and best of all; it burns more calories than walking does.