Our local gunshop here in Milwaukee, WI has a multitool with a .22 cal. pistol as part of the array. It weighs a lot and there is no attempt to hide the gun aspect of it.

Back in WWI, they had pistols built into smoking pipes for spies.

Early large pagers were converted to hold small .22 & .25 semiautomatic guns.

The cell phone bit is nothing new, but very innovative in its construction.

Bountyhunter