Not just for young backpackers, hostels now cater to families and just about anyone who wants to sleep cheap. Unlike the official hostel site (www.iyhf.org), Hostels.com includes lodging unaffiliated with the International Youth Hostels Federation. You'll also find tips for making the most of hostel stays.
Outdoor and Adventure
A compendium of advice for planning an outdoor adventure or finding an outfitter, GORP combines lively feature stories ("Fat Tires in Eastern Iowa") with extensive information on state and national parks.
After a bizarre court case forced the National Park Service's site offline for a few weeks last winter, it's back online with extensive park descriptions and contact info. Online reservations for lodging are available for some parks.
Partnering with National Geographic, iExplore sells outfitted trips, like guided safaris or horseback-riding vacations. Use the search box to home in on trips by selecting region, country and activity. For a more specific approach, click "Trip Search" to select price, duration, departure month, group size and more.
With access to more than 25,000 trail descriptions for North America, this is a superb guide for hiking, mountain biking, paddling or snow sports. Trails.com works with guidebook publishers to provide free overviews of trails. For more detailed advice, you can buy and print chapters of outdoor guides called E-trails.
The Specialty Travel Index of outfitters and trips is sorted by destination and activity, or click "Tour Operator" if you've heard of an outfitter and want to look it up. Using STI is easier than wading through thousands of search engine results, but the listings aren't extensive.
Token disclaimer: The Internet is not a substitute for medical advice from a knowledgeable physician. It is, however, an excellent resource on health hazards and medical conditions abroad, providing advice about immunizations and necessary precautions.
The official site of the U.S. Centers for Disease Control and Prevention includes advice on immunizations, travel preparations and general health conditions. Advisories include recommended vaccinations, tips for staying healthy and essential items, such as insect repellent.
Travel Health Online, which combines news of international health conditions with other foreign travel advice, is frequently updated. Start by clicking "Destination Advisories" for country-by-country health advice on precautions and suggested immunizations. Pages are neatly organized with links to more information on diseases. There's also a list of travel medicine specialists worldwide.
If you travel frequently, especially to remote areas, chances are that sooner or later you'll become sick. Lonely Planet's "Pills, Ills and Bellyaches" specifies remedies for nasty road bugs and includes advice for staying healthy in far-flung places. Also helpful are the sections on predeparture planning, women's health, diseases and ailments, and health links.