This week, the challenge is to invent a hoverboard. Come up with a type that you would actually, personally be happy with, though. So if you're happy with the already made type which works the same as a hovercraft, then that's fine. Or if you're happy with the magnetic one, then that's fine. But still, try to come up with ways they could be improved.
On the other hand, if you aren't satisfied with those real world hoverboards, then try to come up with your own way of doing it. I've come up with two ways (one of which probably wouldn't work, but I'll explain anyway).
Preferably, the hoverboard should be able to hover over a surface without the need of a special track, like a magnetic one does, but again, don't worry too much about that.
Since it's quite late (where I am, anyway), I'm going to update this post tomorrow with my ways of doing it. In the mean time, comment away!
Update: Unfortunately, I don't have access to the site which sells the device used in one of my two ideas, so I can't show you that. I'll just skip to the next one.
So, here's my idea: Get three or four very powerful R/C helicopters, strip them of everything unnecessary, so you're left with only the motors and rotors. Then attach them to the underneath of a large board-like thing, and voilà! You have yourself a hoverboard.
I don't know how much an R/C helicopter can lift, but I would guess the powerful, really expensive ones can lift quite a bit. So if you took off all the unnecessary weight (which I presume is probably about 1/3rd of it), then they would be able to lift even more. Though still, I don't know if that would be enough, but I'm hoping it would.
Another issue is that they need air above them to push down. You could fix this by making the board out of a strong, mesh-like structure, so the air can flow through it.
Of course, this would be very loud. And that's no good, is it? So you could make the rotors silent (or near enough) by putting spikes along the back edge of them. You'd still have the whirring of the motors (if you used electric ones), but it would at least be considerably quieter.
And yes, the board would have to be quite big, but I'd be happy with it.