Ages ago I got a whole load of empty Altoids tins ('near mint' - the wit advertising them described them as) and I'd yet to do anything with any of them. So I made a TARDIS. The whole tin is covered in blue paper and mod podged (watered down PVA glue) to seal and protect it.
Penny next to it for size
This is the inside. The four little characters are on little magnets.
Doctor. Although he isn't really correct sized for his police box
Amy and Rory hang out with the Doctor
Oh no, here comes trouble
Just to give you an idea how teeny this all is (I had my camera's macro setting up to maximum!)