Ken writes -

Here is a link to a model rocket company called Quest. I just found a DIY project on their site that let's you make an Inclinometer (a tool that allows you to measure the height of an object by angle). I downloaded the files and built one - it works great for telling exactly how high the trees are on our backlot property (admittedly - the "real" use is for telling the height of a flying rocket). I remember building one of these as a kid using a protractor and string. This new type is light years ahead.. and pretty cool!

Our Featured Model Rocket Project of the Month! - Link.