Fate would have it that two of our posts today would focus on Legos, but we’re definitely not going to pass up on this one. While our childhood was spent playing with construction kits like Lego & K’nex, connecting together pieces from different kits was near impossible. Ten of these kits are now cross-compatible thanks to the Free Universal Construction kit, a highly-precise (and free) downloadable file containing everything needed to start printing your own pieces using a 3D printer. OK, so we don’t have a 3D printer [yet] either, but we’ll grab the file for when that day comes.

Find out more here – Free.