Video: You can rely on Siri for searching the internet, sending a text message and, err, laying down some sick beats. Turns out that Siri can beatbox — just don't expect too much from it. Ask Siri to beatbox for you, and it will spit out a loop that it's "been practising". You'll hear it repeat the phrase "boots and cats" over and over and over, which is, apparently, a popular starting point for wannabe beatboxers. You can see it in action below, or just try it out for yourself.
Siri can also beatbox (rather better) in Japanese.