Amtrak (http://www.amtrak.com/)
Allows you to review schedules and now even purchase tickets online. Can take a while to get in, but it's useful nonetheless. 

Centers for Disease Control (CDC) and Prevention (http://www.cdc.gov/travel/index.htm)
Under the CDC Traveler's Information section, one can find detailed information on diseases sorted by geographic region, and view extensive lists of recommended vaccinations. 

CityNet (http://www.city.net)
Site contains link lists related to cities including information regarding both local newspapers and tourist agencies, and independent city guides. 

Fodor's (http://www.fodors.com/)
Offers a hotel and restaurant finder, personal trip planner, and bed and breakfast locator, all from a well-established travel source. 

Foreign Languages for Travellers(http://www.travlang.com/languages)
Site lists common phrases for more than 60 languages and has sound files to assist with pronunciation. 

InfoHub Specialty Travel Guide(http://www.infohub.com/)
Have no idea where to take that vacation? Let InfoHub give you some ideas. Has a cool "Find Your Tour" feature which lets you imput a destination, activity, travel period and price range and find a tour. 

The Internet Guide to Hostelling(http://www.hostels.com)
Has an extensive listing of  hostels worldwide, and links to a directory of locations with address, fax, and phone numbers. 

Lonely Planet On-Line (http://www.lonelyplanet.com/)
Basically Fodor's with an attitude. 

MapQuest (http://www.mapquest.com/)
Door to door directions from any location in the U.S. 

Microsoft Expedia (http://expedia.msn.com/)
Your computer travel agent. Allows you to find the best airfare, make hotel and car reservations, get weather information and maps. 

Travelocity (http://www.travelocity.com/)
Exclusive "3 Best Itineraries/Low Fare Search Engine" lets you get three low price quotes from 700 airlines, 34,000 hotels, and 50 rental car companies. 

U.S. Department of State (http://travel.state.gov/passport_services.html)
Site contains information pertaining to pre-trip documents. 

Epicurious Travel (http://travel.epicurious.com) Among the many features you'll find on this site sections on Bargains, Booking, Weather, Photos, Maps, Forums, Bed&Breakfast, and Romantic Getaways. There is also Consumer Help, Reference, Armchair Travel, and Recent Highlights.

Escape on Line (www.escapemag.com/) The site offers some ideas about travel destinations worldwide. You can e-mail the Travel Doctor, who will tell you what shots you'll need depending on where you're going.

Islands (http://www.islandsmag.com/) The site focuses on travel to the world's islands.

LeisureWorld Online (http://www.ompc.com/leisureworld/leisureworld.htm) Covers travel to destinations in US and Canada. Links to other travel sites along with a list of links to AAA and CAA national, state, and provincial Web sites.

Travel & Leisure (http://www.pathfinder.com/travel/TL/) The monthly travel magazine published by American Express has a Web site with many practical information such as weather forecasts and currency exchange rates.