I use Siri while I ride my bicycle. When I'm travelling at an average of 18mph for 2-3 hours at a time, it's hard to pull over and send a text message. Granted, Siri's voice recognition is garbage, but it's still better than endangering my life by texting while biking or pulling over and letting the lactic acid build up in my muscles. Siri sends messages for me, reads messages for me, and calls people for me. I pretty much only use Siri while I bike.