Here’s a bit of fun for any would-be street magicians among you. Card2Phone lets you do tricks with playing cards and common American, British, European and Australian coins.
This video shows the app in action (in the hands of an expert, of course):
Like a lot of tricks and street magic, this is more about sleight of hand and fast moving hands than anything else. But for about the price of a large coffee, it might be just the thing for entertaining some friends (or random strangers).