I have been commiting some time to learning Portuguese. I go to Brasil once in a while for work, and I am almost always around a Portuguese speaker, so for me it is an opportunity to learn. I purchased the Rosetta Stone software for learning Portuguese and I am a little dissapointed. I have heard about people being successful using it, but I am just not getting much out of it. I also purchased Pimsleur’s starter level for about $20. I have gotten much more out of it than the Rosetta Stone. The full Pimsleur set is about $275 per level (3 levels) but I think it is probably worth it.
But, I also think that spending a few months in Brasil would help much more than any language learning course.