http://www.amazon.com/Berlitz-Italian-30-Days/dp/9812682228/ref=sr_1_15?ie=UTF8&s=books&qid=1264822519&sr=8-15 There are more comprehensive courses out there, obviously, but I had five weeks to get ready for a trip and this fit the bill of most possible benefit for a travel situation in the time allotted. Thirty days, thirty short lessons, and it cost me about $25 at Borders.
The trip fell through, but there is a chance my better half and I could pull it off this year, so I'm currently studying this:
http://www.amazon.com/Berlitz-Intermediate-Italian/dp/9812684093/ref=sr_1_10?ie=UTF8&s=books&qid=1264822519&sr=8-10 . This course was actually designed to be the next step from the Basic version (
http://www.amazon.com/Berlitz-Basic-Italian/dp/9812682287/ref=pd_sim_b_2), not the course I started with, but it's working fairly well. I would still recommend that you do the Basic one that was supposed to precede the Intermediate one first (instead of the 30 days course I used).
As for your last question, the "30 Days" course has only one CD, so Pimsluer has more audio, but I can't learn a language well in the early stages without a book to write in, mark up, highlight, and so on. There are Berlitz courses with a lot more audio than the one I started with, but if you're looking for passable conversational ability you can get it from the first course I used, and it really can be done in a month.
My lady, like I, prefers to have a book in the early stages, and she borrowed the following course from her old college roommate: (
http://www.amazon.com/Oxford-Take-Off-Italian/dp/0198603088/ref=sr_1_3?ie=UTF8&s=books&qid=1264823508&sr=1-3), which I think is 14 lessons on five CDs. One word of warning, however: Oxford courses are maddening with their habit of having as much English on their audio as they do of the target language. If, for example, the course book has a "How to use this course" intro, just let me read it, don't spend fifteen bleeping minutes to read it to me on a bleeping CD.
All I can tell you for sure is this: by her own admission as well as mine, I knew a lot more Italian with my one little "30 Days" book and single CD than she did with the Pimsleur course I sent you the link to (which she did complete), and her course had 8 CDs in it. It's your call as to whether you do best with a book or with audio only, but my course as very simply a better bang for the buck, and demonstrably so. If you prefer not to work with a book, I can think of two audio courses I'd try long before subjecting myself to that stunted Pimsleur approach which turns me off so much:
http://www.amazon.com/Italian-Complete-Language-Course-Carrying/dp/1591252105/ref=sr_1_7?ie=UTF8&s=books&qid=1264824214&sr=1-7 and
http://www.amazon.com/Italian-Complete-Language-Course-Carrying/dp/1591252105/ref=sr_1_7?ie=UTF8&s=books&qid=1264824214&sr=1-7 . You can get both for about fifty bucks and learn a lot more than you'd learn with anything Pimsleur could sell you for fifty bucks.
You have to understand that Berlitz must have 50 courses per language, or at least per high-profile language. If you have 4-6 weeks to try to get up to speed, I recommend the "30 Days" course I used, which does cover grammar and provide a surprisingly good foundation given the month or so it covers. If you're determined to learn the language for more than just being armed for travel (the only reason I'd ever need Italian), I might not be the best person to ask about this, but I have used Berlitz for other languages and have never been let down by a single one of their products, not even their phrase books.
The best thing about the "30 Days" course is that it's not one of those which makes a claim of 30 days and take 3-4 months to complete - in 30 days, you can be doing very well and be done with the course. My lady was so impressed with what I managed to do with Italian that she's thinking of abandoning her refusal to patronize big companies and try the "30 days" Japanese version of the course I took.
But as for the comparison you asked for, look at the Amazon prices: her course cost almost 40 bucks for eight CDs and she doesn't speak well. Mine doesn't even cost $25, had only one CD and by everyone's account I speak much better than she does (we both started from scratch, BTW). So the question is this: do you like working with books, or are you an audio-only type?
Last word: you're speaking to someone who is a very satisfied Berlitz customer, someone who insists on a book in the early stages and someone who obviously doesn't like the Pimsleur approach, so I can't claim objectivity - but on the other hand, results are on my side, and even she who refused to try Berlitz is now sorry she didn't.