see how much they could fark up another language?

I did

It wasn't too terrible, and for a Slavik language where an American's tongue isn't accustomed to making those sounds it's a nice tool.

once they start doing cantonese, I'll give it a try

They have Mandarin. Close enough?

And wow - I never realized just how limited their language selection is! You would think for the company that brags about being the best language learning system in the world, they would have a little more selection.

I've always wanted to try Rosetta Stone

I can say god things about it - haven't used it for quite some time now, but it seems to work very well.

The mandarin is very bad. Mainly because their software doesn't truly recognize the difference in tones, and so RS says you're saying it correctly, but real life people do not. Additionally, in their examples they have people from various regions with differing dialects, so sometimes the same words are pronounced differently, and while each is correct in some region of China, it doesn't tell you which region you should use which, and you can only use the version in the example, even if it is incorrect for your shanghaienese etc.

The Mandarin version does have the benefit of including pinyin, whereas the Korean version has no romanization which I find makes it a lot more difficult starting off.

I used it for my tagalog,
but still I only seem to be able to rember the bad words my wife taught me!

I didn't like it at all. The whole time I was thinking I'd much rather have a book to explain things better. They teach you how to say things, but don't teach you why it is that way. So yes, this is how I learned English, but I was also 2 years old at the time, I'd think theres a better way to learn it now.

I kinda agree with Klown's assessment of the methodology, but I do have to say that when I was thrown into the situation of actually having to USE what I had learned (strictly from RS), I found myself to be much more conversational than I believed I could be.

So I dunno, maybe it's good, maybe it's not. To me it's less important to know WHY sentence structure is what it is than to be able to use it properly. If you take things like Serbian padedzi (sp?) for example (something like verb tenses, just more complex and random), if you're not a native speaker you will NEVER learn all the rules surrounding their use...but you can learn them relatively easily with some functional conversation.