I just tried something, the results of which make me very, very curious.
And I haven't even had my first cup of coffee this cloudy Portland, Oregon morning.
On a whim, I typed in: http://calendar.google.com.
I didn't see a calendar app. My multiple-browser test routed me to the it Google home page.
But then things got curiouser. I tried addresses pointing to several other services that Google could conceivably get into one day: auctions.google.com; voip.google.com, phone.google.com.
Repeatedly, my browser spat back a "huh?"
So what does this mean?
Google is real precise in their URLs. If I were a betting man, I'd wager Google is planning a Google Calendar.
Here's how Google Calendar could work. You would register for Google Calendar by stating your location, and your interests. Google ads could be sold that would appear on your Google Calendar for certain dates. They might not be geography-specific, but would be text-prompts for ads containing info about specific promotions, television shows, movie premieres, etc.