duolingo jumped in popularity!
in October I've never heard of duolingo, but recently I've seen it everywhere. it is a very reliable site to learn a new language and I don't see why anyone would use anything else. And I especially don't know why people would pay a few hundred (i.e. Rosetta Stone) to learn a new language when you could search the internet for like 30 seconds and duolingo comes up. I Love Duolingo!
Speaking of the two, this is a nice link Duolingo just posted on Twitter: http://www.google.com/trends/explore#q=duolingo%2C%20rosetta%20stone&cmpt=q