Now I have to say up front that I have not tried this book, but I saw it on the shelf and read a little about it and feel it deserves an honorable mention. Advertised on the box as 'Now with DOUBLE the sounds', I am frankly not sure if that's a lure for the kid or an abjure for the parent! It looked very cool and for around $20 (prices vary store to store) it's not a bad deal assuming the gadgets (motion sensor, light sensor, door alarm, etc) are buildable as advertised and they really work. I used to love this kind of stuff as a kid. Yes! I was the nerd with the chemistry set, and I never lost my love of science!