Southwest.com has made some improvements to their Web site including being able to easily combine your air, car and hotel purchases in one online shopping cart. You can also click the “Join the community” link to communicate with other SWA aficionados to learn more about your upcoming Southwest Airlines destination and more. While you’re on the site, you might want to check out the latest offer from Avis or Budget where you can earn up to five times the credit for renting for five days or more through Dec. 31, 2010, plus up to 30 percent off.