Look, we're not going to go and get all sappy about Logitech shipping it's billionth mouse. After all, we still prefer our fingers for pointing and keyboards for quick navigation around the ol' computer. Still, a claim of one billion served is always notable, be it computer peripherals or hamburgers. Logitech's very first mouse was the Logitech P4 introduced in 1982. For the very first mouse ever, you'll have to contact Douglas Engelbart, its inventor. Or just click on over the break for pics of the P4 and Engelbarts original toothless sawblade.