I'm going to share, day by day, some of my favorite (usually free) ways to educate and entertain myself (and my kids). I will do (at least) 12 days, which will bring us right up to Christmas (yes, I know the 12 days of Christmas start at Christmas. Go away or I'll give you a figgy pudding.)
Today's site is Duolingo, which teaches Spanish, German, and French in bite-sized chunks (there's also learning English for Spanish-speakers, some beta Portugese stuff, and I saw something about Italian speakers learning English).
While not quite Rosetta Stone in approach, it seems similar to me (I've got Rosetta Stone for Japanese, so I can compare).
I'm user meepbobeep (I think searching on that or Mary Pat Campbell will make me pop up) on there, and you can add me to challenge in German, if you want (if you challenge "me" in French or Spanish, you need to realize I'm letting my 9-year-old use my account for those two languages. You'd be competing against her.) You earn points and can level up, like many of these sorts of online learning/personal development sites work.
I basically know no German, and I'm having a hell of a time with the genders and cases. Dammit, French only had two genders and I don't recall the articles differing by case. Also, word order is a bitch. I've gotten up to level 4, which means I can tell you Ich esse einen Apfel (and I probably screwed up that article).
There is an iPhone app, which also works on iPad, that I've found even easier to use than the "regular" computer browser experience.
Another nice feature is that you can ask to get an email at a certain time every day, to remind you about the site. I do one, short unit per day, which takes me about 5-10 minutes, depending how poky I'm being.
The interesting bit about duolingo is the apparent, future business model, which will be a kind of Mechanical Turk as per Amazon (does Amazon still do Mechanical Turk? I did it out of curiosity years ago.) Part of the lessons are to rate or do translations. We all know Google Translate and Babelfish have "issues"... computer processing of language still has a long way to go, and I think it intriguing that they may try "crowdsourcing" translation jobs while the "workers" are learning the languages.