Thanks Lorelai! Even in the current alpha/beta state this application is highly usable. I started with two fresh calendars on the N900 and my two current Gmail calendars. There was no problems with the first calendar but when adding the second there was an error causing the program to crash. I unfortunately did not save the log (by mistake) and restarted the program upon which I noticed that despite the crash all the settings had been saved and sync occurred with no error. Initial sync did take a minute as you had advised. I then tested adding an event on the device and adding a new one on google calendar and there seemed to be no problem with the two way sync.

I will continue to test and report back but this is the functionality I was waiting for to make my N900 really usable and if I could triple thank you I would!

edit : BTW you should really update the original post to let people know that the app has reached one-click install status and is ready for widespread testing. The ability to sync multiple calendars with google is a game changing feature for the built in calendar app.