I know it isn't an investment, but in the last few years some "high risk" investment funds have appeared, and in them you can either lose it all or earn a lot of money.
Isn't this basically the same as gambling? Wouldn't it be faster to just deposit the amount in a casino? At least you'd be able to spend your earnings much sooner

You would probably get better results if you walked into a casino, threw your money on the floor, then turned around and walked out! At least you'd be benefiting by saving on the transaction fees. Probably wouldn't affect your expected ROI as badly either.
EDIT: I'm kidding...don't really try that....they're both bad ideas!