Facebook has begun testing a check-in button for event pages accessed by iPhone users.
A spokesperson for Facebook explained in an email, “We’re currently testing this and it will be available with the next iPhone release.”
The check-in icon only shows up on the day of the event and only when users are geographically close to the specified address.
In the mean time, perhaps you could help us fill in some of the blanks: Readers, have you seen the check-in button show up on an event you’ve been invited to?
Props to Kevin Evanetski for the screenshot and tip.