I'd be interested to know if Google Now can do people reminders. Unfortunately I sold my last Android device so I'm unable to test it myself, but a quick search brings up this article[1] which suggests that it doesn't exist yet. Either way, I'm sure it's only a matter of time until both Siri and Google Now can do it too (which is a good thing, I've found it incredibly useful).
[1]. https://support.google.com/websearch/answer/3122344?hl=en