First Science Week Post : My Favourite Invention from Childhood
As a kid my favourite invention had to be Lego (the old style stuff where you built stuff from blocks as opposed to the new style where you connect the wing part to the body part). I spent hours in my bedroom constructing whole worlds from collections of basic pieces. A simple idea only made possible by the existence of low cost manfacturing and cheap plastic.
Lego lasts forever (pretty much) which means all the lego you had as a kid is useable by your kids. How many other toys can you say that about?