Sync your Lightning with your iCal
I love Thunderbird, so I use Thunderbird + Lightning instead of Mail.app + iCal as my personal schedule and mail solution.
Also it's promised to have a syncing feature, it didn't have now. But I need the ability to sync my schedule with my Palm Treo 680. I can sync my Palm with iCal, so getting the linkage between Lightning and iCal is a good way to do this.
First, I installed the Provider for Google Calendar extension to get the bidirectional access to Google Calendar to Lightning.
Then, I use GCALDaemon to sync my iCal with Google Calendar. It can also sync Google Calendar with Lightning, but Provider for Google Calendar is much better at this.
Now if I add/modify/remove an event in Lightning, Provider for Google Calendar will update my Google Calendar immediately. Later, GCALDaemon will find the update, and update iCal. Now I sync my Palm with my computer, it will get the update.
If I update an event in my Palm, and sync it to iCal, GCALDaemon will update Google Calendar later, and then Lightning will update it later.
So it works.
Make a symbolic link with the ics file of Lightning and iCal may also work, but I can't find the ics file for Lightning :P
You can subscribe my busy/available status on Google Calendar now :)
This should also works for Mozilla Sunbird.