Regional bicycle touring is popular. It means coasting along winding backroads (because bicycles are often not permitted on freeways) and calculating progress in miles per day, not miles per hour. Cyclists must follow the same rules of the road as automobiles, but don't expect drivers to respect your right of way. Better World Club (www.betterworldclub.com) offers a bicycle roadside-assistance program.
For epic cross-country journeys, get the support of a tour operator; it's about two months of dedicated pedaling coast to coast.
For advice, route maps, guided tours and lists of local bike clubs and repair shops, browse the websites of Adventure Cycling (www.adventurecycling.org) and the League of American Bicyclists (www.bikeleague.org). If you're bringing your own bike to the USA, be sure to call around to check oversize luggage prices and restrictions. Amtrak trains and Greyhound buses will transport bikes within the USA, sometimes charging extra.
It's not hard to buy a bike once you're here and resell it before you leave. Every city and town has bike shops; if you prefer a cheaper, used bicycle, try garage sales, bulletin boards at hostels and colleges, or the free classified ads at Craigslist (craigslist.org). These are also the best places to sell your bike, though stores selling used bikes may also buy from you.
Long-term bike rentals are also easy to find. Rates run from $100 per week and up, and a credit-card authorization for several hundred dollars is usually necessary as a security deposit.
Some cities are more amenable to bicycles than others, but most have at least a few dedicated bike lanes and paths, and bikes can usually be carried on public transportation.