Rosetta Stone WORKS
I studied Spanish, starting at the third level. I was in a new job where I was dealing with a lot of clients with limited English, so I needed to get my Spanish up to speed FAST.
It was extremely effective. I used the program for a couple of hours a day and really drilled on the upper-level grammar. Even if I wasn't communicating perfectly, I could get my point across, and more importantly, I could understand my clients! That was a big relief to both of us, as well as my boss.
I definitely used this in the real world, in a lot of routine business situations. It also sure came in handy when I was traveling in Mexico and South America for business. People were delighted when they learned they could communicate with me, at least on some level, in their native language. They felt much more comfortable, and I felt better, knowing that I understood what was going on. There were less chances for miscommunication or other big problems that could have made a real mess for us.
I would recommend this program. It's ridiculously expensive, so see if you can write it off on your taxes as a business expense or something, but if you are trying to learn a language fast, this is the way to go.