Does Rosetta Stone really help you learn a new language and the culture of another country?
Rosetta Stone is effective but only if you're terrible at learning new languages. It teaches you at a very slow and repetitive pace as to drill the words and phrases into your head but it works if you're really desperate. As for the culture, there are cheaper methods to learn about the culture of another place, just read ! All levels should run you around 500$.
If you are able to teach yourself some of the language or find a tutor, then it's much more better.
How good are the Rosetta Stone language training tapes?
Rosetta Stone doesn't use tapes - it uses interactive software. It's actually pretty good! This is in part because it doesn't use your native language at all - you associate new terms with pictures of the object or idea. It basically works by quizzing you constantly. There's no grammar lessons or vocabulary lists - you just figure out the grammar as you go along. In that way, it's much more natural than other systems. It's not magic, but I'd say it's at least as good as taking a university course (if not better).
It's got a variety of sections (auditory only, writing, reading, speaking, etc.), and I actually thought it was fun. But I'm a huge nerd who collects dictionaries in foreign languages. So...there's that.
How good is Rosetta Stone for learning a new language?
Rosetta Stone is great program, you can read reviews here (the majority are positive reviews, and they are reviews from actual people who bought and used the exact program you'll buy, not people who 'speculate'):
An alternative is Fluenz:
As for the price of these high-end software programs - you'll find that they are actually cheaper than alternatives. A tutor will cost anywhere between $20-$60 per hour, and you'll need at least several dozen sessions before you become even 'OKAY'. A Uni / College course will be $1000+ and a $100 + for textbooks (and you'll need to take it for at least 2-3 years).
If you're really tight on cash, you can get a decent program for like $30:
How does Rosetta Stone work for languages using a different letter system?
I learned a bit of the Thai-language. I had a private teacher in the country, but just speaking and just the essentials and only a very short time. A friend sent me a Rosseta-Stone beginners version for Thai. I tried it and I mentioned that I become able to classify some signs to sounds. However, Rosetta Stone wasn't the only source for learning.