I’ve started to use Mozilla Sunbird for my windows calendar application because I can share ical calendars between Windows and Mac on my webDAV. The problem was there was no way of automatically sharing my calendar with my iPod. With a little searching, I was able to find an extension called Automatic Backup that will enable you to copy your calendar to other applications (like your iPod) as well as save multiple dated copies for backup.
After installing the extension and restarting Sunbird, you need to open the options for Automatic Backup and set the folder location which should be the calendar folder on your iPod. You just need to ensure that you have the “enable disk use” option checked in iTunes, so that you can access the calendar folder through Windows Explorer.