I will be doing to Alaska from July 10 to July 20, 2007. I was fooling around and try to make my car reservation now. Much to my surprise Hertz reservation center would already accept my reservation. I was able to rent a compact Ford focus for the 10 days at $439.35.
A10-day rental for the same car to rent July 17 to July 27, 2006 the rental price was $1531. If you can figure out your plans well in advance, it pays to shop early.