A friend of mine just pointed me to a great ASL resource, aslpro.com. It has a wonderful video dictionary of many basic ASL signs, and even has an "ASL for Babies" section. This is especially useful to me because I'm currently designing a baby-focused program for a library that will incorporate signing elements.
aslpro.com also has a fun "Quiz Me" feature that plays entries from the video dictionary and asks you to identify which sign is being made. Teachers can even create an account and personalize quizzes for their students.
Of course, this website isn't designed to replace face-to-face ASL learning, but it is a great resource, in particular for those who want to see demonstrations from people other than their instructors. Enjoy!