Here's a product that brought a flood of memories to mind when I came across this photo recently.  

The FlowBee Home Haircutting System used your own vacuum cleaner, along with an attachment of dangerous spinning blades to give you that perfect solo style.  Notice the young boy in the sequence of photos.  He's giving the 'thumbs up' at the end.  He's happy with the results. 

I remember thinking that this was amazing about 20 years ago.  I even asked my mother to buy it.  She said it was a bad idea, but I think she was wrong.  Just imagine all the money we would have saved.