Use it for a flying saucer hoax which will cause mass panic about oncoming alien invasion.
Line it with little mirrors, tinfoil, ect to create either a large spotlight or a solar powered satellite dish cooker.
Use it as a giant Guacamole dip dish.
Build a parabolic reflector mic.
Use it to build a 1920s style “Death Ray”.
Enhance the hit-surface of the toilet bowl.
Use it as a snow saucer, a protective cup or cover it with glass and turn it into a table.
Put some holes around the bottom to use as a colander when making large amounts of spaghetti.
Use it to surf on open wireless networks on the other side of town.
Make a birdbath out of it (which was my very first thought).
I could go as the Gladiator to my next Halloween party or just wear it as a large, silly hat -or a hat for rice patty farming.
Build a swimming pool for midgets.
Use it as body armour in a gunfight, a la, Senor Eastwood.
The base of a fire bowl for summer evenings.
Tie myself to a speedboat and use the dish instead of waterskis. -AKA “Waterdish’ing”.
Snail racing Indy 500 style, grease ’em up and watch them crash.
I could mount a magnetron from an old microwave oven in front of it and cook food on the other side of town (AKA a 2020s-style “Death Ray”).
Use it as a giant Wok.
Bury it in my yard, convex side up, leaving the topmost portion of the round visible through the dirt. then put some stakes around it and rope it off, and put a sign beside it that says “DANGER! UNEXPLODED LAND MINE. STAY BACK 50 FEET.”
Attach it to the top of my car. and get vanity plates that say “MTHRSHP” OR attach it ‘correctly’ to the top of my car and pretend I have satellite TV in my car.
Use it for the Oversize Discus competition or as a giant Frisbee.
Put a base on it, have a bunch of people over for the superbowl and serve chips and salsa out of it.
Enjoy a really big bowl of soup.
Make a directive speaker and broadcast audio propaganda towards the house at the end of the street.
Put a strap on it to turn it into a shield, arm yourself with a light saber, and head out to the nearest Ren Fair armed with futuristic technology.
Build a model of the starship Enterprise, using the dish as the main hull.
Sell on Ebay. Somebody will find a use for it.
Bolt it to the top of a black van and spray paint “Flower Delivery” on the side and randomly park in front of crackheads houses to make them paranoid and shoot themselves.