Three of the four programs shown below have audio which would require the user's desktop be equipped with a sound card, speakers and access to RealPlayer:

Learn Spanish Online. This very basic site is for the dedicated self learner who has little or no background in Spanish. There is audio for pronunciation and scored exercises to gauge one's progress. The user should be able to make simple sentences upon completion of this program. http://www.studyspanish.com

Spanish for Travelers. Definitely for the business traveler. Here the user will learn the basic phrases that will help while traveling to Latin American countries. Additionally, there are translation dictionaries and programs linked to this site. Audio capabilities required.
http://www.travlang.com/languages/cgi-bin/langchoice.cgi?page=main&lang1=english&lang2=spanish

Spanish Vocabulary Builder. As the name implies, this is a vocabulary building site. Clicking on the picture, allows the user to hear the Spanish pronunciation for the pictured object. http://languageadventure.net