Many companies in the United States and the United Kingdom offer overland backpacking trips for large groups. You and 39 others hop on a retrofitted Mercedes bus for a one- or two-month tour that could begin in Santiago, Chile, or São Paolo and end in Lima, visiting Cusco, Machu Picchu, and all the other sites along the way.

These companies strike bargains with hotels ahead of time and take care of all food, lodging, and transport. These trips move like an army, camp on beaches, advance along the Inca Trail, and leave behind a litter of soap opera romances. With a two-month trip costing around US$3,000 these trips are about as good of a value as you are likely to find. A pair of budget-minded travelers could, however, do the same trip for the same cost or less. Last-minute web specials often offer 25 percent discounts on these trips.

The best agencies to look at are Kumuka (www.kumuka.co.uk), Bukima Adventure Travel (www.bukima.com), Dragoman Overland (www.dragoman.com), and South American Safaris (www.southamericansafaris.com). A final highly recommended option is Australia-based Tucan Travel (www.tucantravel.com), which offers a range of trips including language schools and custom packages for independent travelers.