Recently I started to take the andvantage of Google Calendar - it is nearly available everywhere you get internet access through a browser. But, as compared to Gmail, there is IMHO no mobile version around yet. Third party Gcalsync  did not really work satisfyingly or at least not the way I wanted to have it to work.
So, with the help of two tools that situation changed completely. Firstly there is to name MyPhoneExplorer (MPE) written by the Austrian Franz Josef Wechselberger . MPE runs on Windows. It is originally intented to work with Sony Ericsson mobile phones, since recently it also deals with some Nokia file formats. It handles remote and - since version 1.5.9 also - local .ics files. This file format is used to handle calendar information.
MPE also deals with various remote calendars. So it should now directly work with Google Calendar. But I did it another way round. Since Thunderbird/Lightning was/is my standard email and calendar tool locally there was yet more interest to sync this tool with Google Calendar. But Thunderbird/Lightning currently only fully snycs with Google Calendar via another application called GCalDaemon , a daemon tool running locally.
All three calendar sources - via mobile phone, Google Calendar online or Thunderbird/Lightning locally - are being synced via a local file that I called google.ics. The combination runs perfectly since the release of version 1.5.9 of MPE in February.