Some years ago I had an idea for combining a pair of electric hair-cutting clippers with a vacuum cleaner, to produce a hair cutting tool which would suck all the cut hair away rather than depositing it all over you. It’d also work in zero-G, and if you put appropriate attachments on the front you could cut hair to set lengths just by running the hand-held nozzle bit over your head. The hair would be sucked straight, trimmed, then the loose hair would be vacuumed away, all at once.
After a day or so of musing about it, I decided it was a stupid idea.
Last year, I saw it on “Tomorrow’s World” as a brand new patented invention.