Toothbrush with plunger device, 1930

Now why didn't this one catch on? Save yourself the hassle of using one hand to brush your teeth, and instead use one hand to hold the toothbrush while using the other to push a plunger in and out, which causes the cleaning head to spin around, thus cleaning your teeth.

Brilliant.

Bed Cooling System, 1959

This is a "cool" idea! Its a sleeve that goes over a standard house fan and can be tucked under the bedcovers to keep one cool on hot nights. This young lady certainly seems to be enjoying the breeze blowing up from the lower regions.

Alternatively, she could just remove that heavy quilt.

Skycot, 1955

"Please take care when opening overhead compartments as items move around during flight."

Automatic Bartender, 1956

This automatic bartender (the machine, not the woman) was designed to mix a drink in 3 seconds. Upside - you get your drink in 3 seconds. Downside - no bartender to listen to your drunken ramblings or dispense sage advice.

Although this one never caught on, people obviously think it's a good idea. A quick search on YouTube shows literally dozens of contemporary versions of this, ranging from the home made to the technically advanced. This is my favourite: http://www.youtube.com/watch?v=9IfJywRrcRw&feature=related

Hands Free Phone, 1945

Actually I like this one. Simple, concise, fills a need - talk on the phone at work while you do the crossword and smoke!

Is it just me or does this guy look like Kevin from The Office (US version)?

Motorized Roller Skates, 1926

The first time I ever saw motorized roller skates were those worn by one Wyle E. Coyote in a brilliant, but thwarted, attempt to capture a road runner. However, this pair, designed and built in Germany by an engineer named Gerhardt, predated the Acme Company's version by decades. The idea never really seemed to take off, so to speak, until quite recently: http://gizmodo.com/314473/ishoes-movin-and-groovin-at-15mph I'm still trying to work out where the brakes are.