This product is probably one of the things that has brought back the most nostalgia for me.
I loved playing with die-cast cars as a little kid, and still have a carrying case full.
This makes me want to whip out the cars and some paper (or maybe I'll just design a course on my rug with Legos or something) and play with them again.
My only gripe is the small size, and the price. For 9 pages, it's not terribly long. But if it's what you need to get you off your computer and playing, it's worth all five dollars.