Doritos has something called Collisions, which allows you mix your own music, create lyrics, sing them to the music, and then email to a friend. You can then post the url of your recording for all the world to hear.
Singing is a great way for English Language Learners to begin to feel comfortable with the language.
The great thing about this site is that you don’t have to register before creating a song and emailing it. Other “viral marketing” sites that have similar features require some sort of registration.