Free Universal Construction Kit. You need access to a 3D printer for these, but they're universal connectors that let you connect different types of building toys--Lego, Duplo, K'nex, Tinkertoys, etc.--to make giant Frankenstein projects. 3D printing is really poised to take off because of things like this. @MommaB2C
Wiki page on Henry Dreyfuss, the guy who designed the classic round Honeywell thermostat, the Big Ben alarm clock, the models 302 and 500 desk phones, as well as the Princess and Trimline models. He also designed trains, vacuum cleaners, and just about anything else people used. He died in 1972, but many of his original designs are still being sold and even more are still being used today.