Besides using it as a fertilizer, how else can I reuse my coffee grounds?
A friend of mine (who lived in a van) always used it as a replacement for soap when washing hands. Seemed to work quite well :)
It's an abrasive. As long as you don't mind the coffee smell/stain, you can use it to clean and polish surfaces.
A friend flushed them in the sink, he said that it cleans the pipes. But then I don't really know if it's true except his sink never got stuck. But that's not a proof!
cooking wise, they're so bitter/burnt. The water already took the good flavor out of them and left the crap behind.
From the previous answers, it seems that using coffee as an abrasive or any other way will require a clean up after using the grinds, which in my opinion makes them useless.
It's supposed to keep cats from crapping in your yard. Just toss it on the ground and apparantly they'll take their business elsewhere.
An actual culinary application for used grounds: http://www.instructables.com/id/Gourmet-mushrooms-in-an-old-coffee-cup/
Grow mushrooms in them.
You can put it in a small dish inside your refrigerator. It will kill bad smalls and leaves a nice coffee smell. Note: Baking powder also works fine but without leaving any smell.
For those who collect kitchen scraps for composting, used coffee grounds are a great deodorizer for your compost pail, especially in large quantities (like if you do a batch of cold brew).
I myself use it as a universal scrub. Coffee grounds are much softer than the mineral abrasive or crushed apricot seed scrubs, and (unlike the latter two) it does not cause skin irritation, at least for me.
I typically wash it to remove tiny particles (so that it does not stain the tub so much) and then soak it in diluted hydrogen peroxide in a refrigerator until I need it.
The only thing you should re use coffee grinds is as a roach deterrent, Roaches hate coffee grinds and if you take your coffee grinds and place them in areas you see roaches congregate..they will find another place, It even can get rid of them all together. Reason I know this is I am anti pesticide and herbicide. There are so many natural alternatives to bug spray..and coffee grinds is one of them !! so reusing coffee grinds for coffee is plain awful. I had a uncle who used to dip copenhagen tobacco, He also would re-dip ie: take the wad of wet chewing tobacco out and later on re use it..I thought it was plain upsetting not to mention a bit disgusting..I think re brewing coffee grind is not as bad as that but not much different either (they sorta look the same too after being used)...gary