I've written about Petra Lingua before, sharing my experience with the program that I have used for a while, when I started teaching my daughter French, eight months ago. Since I have written that review only in Romanian, I've decided that PetraLingua deserves a post in English, too!
A couple of months ago I was fortunate enough to win a giveaway on Multilingual Living, consisting of 3-months access to any of the PetraLingua online language courses for kids. Since my license had just expired, I chose French again.
I really like the way they easily introduce children to foreign languages - in a fun way, and yet not overwhelming. There are lots of exercises that you can choose from, to fit for children between 2 and 11 years old, to practice and reinforce the concepts in each lessons. There is interactivity, not just mere TV watching. You can read more about the method and you can also try one of the online language classes for free.
So, yes, we enjoyed it, learned a lot from it and would gladly recommend it especially to parents that don't have many resources to teach a foreign language (or they don't speak it very well themselves) - the online support is very helpful in these cases.