Here are two of my inventions.  They may be wacky or trickful, but they’re still useful:

1.  Ice Cream on the Rails — This is a train car that makes ice cream cones and lets you see them being made.  First, the side doors open on the car and then there’s a hole in the wall of the car.  A scoop of ice cream falls out of the hole and onto a ramp inside the car.  Then it gets picked up by a thingy (sort of like a spoon), which flips it onto another ramp.  Then it falls a bit, and a cone shooter shoots a cone under it.  Then it goes on a conveyor belt with holes to hold the cone.  Then the sauce gets put on it and the sprinkles get put on it, and it hands it over to you. (You have to be standing next to the railroad track to get a cone.)

2.  False Rocket Boots — It’s ski boots with four heavy-duty fans attached to each one, so you can actually fly, and two burners attached to the bottom.  The burners imitate rocket flames, but they’re not real because it’s too hard to put real rockets into boots – you’d just fly right up into space.  That’s why they’re “false” rocket boots.  But they’re really nifty for getting home fast.