Innovative mechanical or electrical really cheap toy

[agnibho]

Homework Statement

OK, this is a project given to a group of us. I don't really know whether this is a homework question, if it isn't please correct me frankly. We need to make a toy that is really cheap, and quite innovative. I don't need any suggestions whatsoever, but I have got some ideas, I need you all to simply rate them.
2. Attempts and ideas
Well, I was thinking of a magnetic levitation toy, which can be kept anywhere and be carried around easily. The making is simple for us too. But will it pass the criteria for the project that I have stated in the question section??
Also I thought about a hovercraft, the one with a balloon, a plastic disc and a small tube. You need to pierce a hole in the center of the disc wide enough to tightly hold the tube and then place the filled air balloon on the tube. It can traverse water and even land.
The next idea was a hydraulic crane. Now this isn't quite cheap and has a lot of complications too.
These are not quite innovative as to say...but um...I need help here.

 

[Sunil Simha]

The crane would be the best one and can be made cheaply using disposable syringes.

 

[agnibho]

Thanx well, we did the crane itself and won the first prize!

 

[Sunil Simha]

Congratulations.

All the best for your next round.