The method is very good in terms of constructing sentences with ease. I don’t know how Rosetta Stone compares but MT was available in my local library. It’s Egyptian Arabic though but i’m going with it anyway.

is busuu.com. I’ve never done any of the Arabic stuff but I’ve greatly expanded my French and Spanish vocabulary on there. The set up is visual and audio which I think helps (similar to the flashcard thing again). You can also pay for a premium account…although I can’t personally speak on the difference. Plus there is plenty of opportunity to practice, writing posts that native speakers will correct or trying to live chat with someone once you can sting some sentences together.