Read more here, including code samples:
Until yesterday I'd only tire-kicked Google Calendar. I couldn't use it for real until I loaded it with real data. Last night I finally got around to doing that. In my case, the export/import path led from Mozilla Calendar to an XML representation of iCalendar format to Atom and then into Google Calendar. The hero of the piece is Joe Gregorio, whose wonderful Sparkline service I highlighted a while back. Joe is also, and rather more notably, the author of both the Atom Publishing Protocol and Python's httplib2 library, two projects that came together to facilitate my transfer of calendar data (see script below).
Google's Patrick Chanezon had alerted me to the fact that Joe has added a new authentication scheme to httplib2. Along with HTTP Basic, Digest, and a couple of others, this Python HTTP library will now handle Google-style authentication. That's really the only tricky thing about using Google Calendar's API. Everything else is URLs and Atom entries. There are Java and C# wrappers for this stuff, but I'm having a ball just using Python's interactive mode to explore the Calendar API. Among the things I can easily do: search for entries matching dentist, search for entries after June 10, receive the results of any query as an Atom or RSS feed.
My TorDemoCamp demonstration (here and here) of what you're looking at here also had Google Calendar integration, using Microformats to read the calender information. Alas, not only was it a little flaky, it has the sample problem Udell's demo does: you cannot create a service to put data into Google Calendar without giving up your Google password. There may be a way to create a secondary Google account, but I haven't delved deeper into this yet. It'd hardly be fair to ask people to put their super secure Google password into our app and you'd be a fool if you were the one doing it.
