As I have already said variety is the spice of life, and while no computer software or DVD of foreign language cartoons will keep your child interested forever or make them bilingual, it will improve their language skills. For example, watching cartoons in French will inevitably improve their accent, and they will subconsciously pick out words that they already know helping to reinforce and internalise them. The same can be said for language learning software, which is that it is a useful complement but not a substitute to formal learning. Linguata would help.