04.18.06
Google Mail + Calendar
I’m pretty sure this “Add event info” button wasn’t there in Gmail Friday. I wonder what it does. Time to play with it. 
I have found out that Google Calendar doesn’t do anything with emailed accept/decline/tentative responses out of iCal, which is unfortunate. Maybe this button means they’re making changes quickly.
Update: from Google Calendar Help,
Why doesn’t my Gmail have Google Calendar related features?
It may take a few days before your Gmail account displays Google Calendar related features. We’re working hard to roll out these features to all Gmail users, and we appreciate your patience.