In keeping with my inner (outer?) geek, I love poking around this site on all things old and mechanical, which are all over the KMODDL maintained by Cornell University. 

From the site's home page:

KMODDL is a collection of mechanical models and related resources for teaching the principles of kinematics--the geometry of pure motion. The core of KMODDL is the Reuleaux Collection of Mechanisms and Machines, an important collection of 19th-century machine elements held by Cornell's Sibley School of Mechanical and Aerospace Engineering.

Check it out if you'd like to see where some of our current mechanical beasts had their start.