In my personal experience, you'll get more out of two weeks with a good teacher than you would in 2 months with a book/CD.
One problem with the book/CD method is there is no one listening to you. So although you might think you're exactly mimicking the voices on the CD, you really might not be. A teacher can make immediate corrections to you when you're speaking and give you feedback as to how understandable you really are.
That's not to say that books or CD's aren't helpful. They really can be for the right person. I'm just not one of them.
If you're not in an area with a large Spanish speaking community, it may also help to take a class with others, so you can make a friend to practice with away from class.
I know what you mean though about taking HS classes. I took 3 years of Spanish in high school (19 years ago), but didn't use it all that much after. But back in 2004 I took a trip to Central America (Panama) and was pleasantly surprised how much of it came right back to me. I think you'll be amazed how much of your HS Spanish will come out of your brain storage area right when you need it. 
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