Microsoft Paper Air Plane challenge
For this one i have to thank Flight Global as i first saw it there. The Paper Airplane challenge game from Microsoft is just fantastic fun, as you just press your mouse on the paper plane and easy as you like try and fling it across the office and out of the window, where it can go a very long way. For ages i couldn't even get it out of the window so my tip is to fling it as hard and as low as you can (without hitting any furniture) because once it is free from the first room it can go a distance. You can also create a league if anybody is interested.
My current best is about 80m but i think that is pretty rubbish really compared to how far you can throw it.