Here are useful links plus other relevant sites for traveling:

Airlines:

America West: www.flyawa.com
American: www.americanair.com
British Airways: www.british-airways.com
Continental: www.continental.com
Delta: www.delta.com
Northwest: www.nwa.com
Southwest: www.iflyswa.com
United: www.ual.com
US Airways: www.usairways.com

Car Rental Companies:

Alamo: www.goalamo.com
Avis: www.avis.com
Budget: www.budgetrentacar.com
Enterprise: www.pickenterprise.com
Hertz: www.hertz.com
National: www.nationalcar.com
Thrifty: www.thrifty.com

Online Travel Agencies:

Microsoft Expedia: expedia.com
1travel.com: www.1travel.com
Priceline.com: priceline.com
Smarter Living: www.smarterliving.com
Travelocity: www.travelocity.com

Travel Magazines and Sites:

Fodor’s: www.fodors.com
Lonely Planet: www.lonelyplanet.com
Roadside America: www.roadsideamerica.com
Rough Guides: www.travel.roughguides.com

Other Resources:

Google Groups: www.groups.google.com
Eurail: www.eurorail.com
Lonely Planet’s Thorn Tree: www.lonelyplanet.com/thorn/thorn.htm
Yahoo! travel directory: www.yahoo.com/Recreation/Travel