Gadget Category Answered

No need.  Simply file by the gadget's function.

A gadget to feed the dog while you are out goes under pets.  A gadget for separating eggs goes under food etc.

If it doesn't any other category, then it goes in offbeat.

.  Sounds like a good idea to me, too ... but where do you stop? There will always be one more great category subject, but after a while it just gets cluttered and harder to find stuff.
.  But that's just my opinion. Maybe Robot will go for it.
.
.  Encourage ppl to use "gadget" in their keywords (where applicable).