Ok lol I signed up just to reply to this thread
First off Rosetta stone is a waste of time and if you are buying it legitly it's a major waste of money, the reason why it costs so much isn't because of the quality but because of how much money they put into advertising, which is probably why you have heard of it too. I tried it out, the only things gained really were a few words and better pronunciation.
Instead learn use things like tae kims guide / complete guide to Japanese. Or splash out and buy a text-book like genki, basically there are tonnes of cheaper or free alternatives that will give you a much better understanding and skill in the language.
And to ctcdreamer/Kurisutaru:
The sentence structure of Japanese isn't something that can be said like that, for example a complete sentence in Japanese would be taberu (食べる), which is just one word but would equal a sentence like I am going to eat or He is going to eat or I am eating or she is eating (you get the drift). So you can't really compare Japanese to English, they are not alike.
As for your comment about looking words up in romaji, trust me once you can read hiragana you will never want to look back at romaji, it's horrible. Just spend a little time learning Hiragana and katakana and then learn Kanji over time