Just want to say, I've started using Duolingo and it's fantastic! Poster up top says it won't get you fluent...I'm not so sure!
If you have a microphone it gets you speaking phrases and translating phrases out loud, it also says all phrases out loud which you can translate from.
I'm learning German at the moment, I did it at GCSE nearly 10 years ago, I've forgotten most of it but I'm certain I have a better grounding of the framework than I did back then. It will be interesting to see what sort of level I can get up to. It's very easy to practice particular sections which can really help ingrain the knowledge.
If it gets me to a level where it's possible I think I would even consider getting an A-Level in the language. I'll have to see just how good it is!
Oh, and there is an app on your phone so you can practice in your lunch hour. You can disable microphone inputs if you're in a public place.