I found this cool use of Legos and CDs on Natalie Solent, a blogger who sometimes posts about technology issues.
The completed sextant
What can this sextant be used for? It fulfills the state objective for teaching about the early history of science, as well as giving students the opportunity to make an instrument that they can use to locate their position on Earth.
An early sextant
A good follow-up activity is to show them how to use GPS units.