It's surprising how many iPhone users don't use Siri for some quick tasks on their iPhone 4s or later. Apparently, Apple is also disappointed at the low adoption rate. They've recently created a Siri webpage to remind iPhone users (and future Apple Watch consumers, no doubt!) of some of the digital assistant's capabilities.
Our favorite use of Siri is creating reminders; simple say "Remind me to call Mom tomorrow at 3PM!" In case this subconscious, guilty request for a reminder happens to occur at 1AM after a scandalous night out, Siri is even smart enough to ask for clarification about whether "tomorrow" refers to later the same day or, technically, the following day.
Take a look at Apple's Siri page here.