I was given a calculator for Christmas - it's amazing the amount of words you can make with numbers and then turning the calculator upside down - WOW! - the list is endless - who needs an Xbox for hi-tech entertainment??
Dare say that these will take off in a big way once word gets out.
There's a sum you can do, something along the lines "she started out with 2, then six of her friends turned up which gave them 14 blah blah, and then they all ended up.....", it then gives you the answer 55378008.....(think about it...!)