Recently, Apple has provided Siri with a couple new tricks within her capabilities. Now you can ask Siri to "Flip A Coin" and the response will typically be either heads or tails...aside from some humor responses.
Check out this video by SiriHumor on YouTube for Flipping a Coin with Siri:
Siri can also pick a random number, and will provide the results of two 6-sided dice. Perfect for that impromptu game of Craps. YO!