For me I used it to make this alethiometer from the book Northern Lights (aka the Golden Compass in the US) and shortly to be released as this Christmas's big hit, the Golden Compass. Which looking at the trailers is a mixture of Riven (the game for those that know), Steam Punk and a bit of Round the World in 80 Days thrown in for good measure.
Full instructions on how to use this instructable to make a Golden Compass can be found on my website dadcando here, including free printable templates for all the graphics and an accurate profile template guide.
But then you can make loads of round things using this method... I'm sure you'll think of them. Post pictures here if you do, we'd love to see them.
Step 1: Make the basic shape
Model Maker's TIP #1
If you model is of something that has weight, i.e. it is made out of metal, plan to fill it with some ballast. This will make the final model much more realistic and fool people into thinking that it has been made out of metal, or has more of a quality feel to it. But be careful not to stick anything over the centre hole area, you are going to need to be able to poke something through the card right there in the next step.
In this case I cut two discs and then used up right spacers to make sure they were at a constant space apart and then wrapped a piece of card round the assembly to give me the disc shape.