Small Step: Rent a flat in London. Visit Net-Lettings.co.uk to browse rental listings.
Giant Leap: Relocate to Cairo. It's welcoming to nonnatives and boasts stunning architecture, an opera house, and an international film festival. For emergencies, take along Cairo: The Practical Guide, by Claire E. Francy.
Competing in a Triathlon
Small Step: Try a short-distance event—some require just ten minutes of swimming, 30 minutes of biking, and 20 minutes of running. TriFind.com lists local races.
Giant Leap: Tackle an Ironman (2.4-mile swim, 112-mile bike ride, and 26.2-mile run) and compete for a qualifying slot in the World Championship (Ironman.com).
Hiking the Appalachian Trail
Small Step: Go on a daylong trek; the Mid-Atlantic and Virginias segments are the least strenuous.
Giant Leap: Take on the thru-hike (all 2,178 miles) from Georgia to Maine—giving yourself at least six months to make the journey. Find a description of each leg of the hike at AppalachianTrail.org.
Owning a Business
Small Step: Open a franchise. Find a company you like—whether Baja Fresh or Gymboree—and visit its website to learn criteria and find applications.
Giant Leap: Create your own business model. Get info on loans from the Small Business Administration Web site (SBA.gov).
Writing Your Story
Small Step: Start a blog—go to Wordpress.com and you'll have your page up pronto.
Giant Leap: Write a memoir. New York City's Gotham Writers' Workshop offers online classes on personal history writing for $395 (WritingClasses.com); Natalie Goldberg's Writing Down the Bones can also help you get started.
Travel cross-country, go on a safari and more