If you've never watched an online lecture from MIT, you are apparently in the minority. According to recently released statistics, more than 10 million people are now using MIT's OpenCourseWare Project. The OCW shares syllabi, exams, notes, problem sets, lectures, and even some discussions for just over 2,000 courses. (Discussions are held through online study groups using OpenStudy.
This site contains libraries of phonetic sounds of English, German, and Spanish. Available for each consonant and vowel is an animated articulatory diagram, a step-by-step description, and video-audio of the sound spoken in context. It is intended for students of phonetics, linguistics, and foreign language. There is also an interactive diagram of the articulatory anatomy.