I used Rosetta Stone's Italian language program prior to my two cycle tours in Italy, I thought it helped a lot. I'm continuing with Italian Level II sporadically, in hopes of getting back to Italy for another visit.
I also like Pimsleur language CDs. They don't help as much with grammar or spelling as the Rosetta Stone program, and you don't have the pictures to help you remember. I used the Pimsleur CDs walking to work for a while (expect people to really look at you funny), and I also used them driving in my car if traffic and road conditions permit.
The Pimsleur CDs are a good supplement to the Rosetta Stone program, Rosetta Stone is the better stand-alone system.