calendaring

I’m determined to become more organized and keep better track of what I’m supposed to be doing and when. I think I have a good set of tools at my disposal, but I’d like them to be better. I have te Calendar Extension for Mozilla Thunderbird installed on my WinXP desktop at work and Kontact/KOrganizer on my laptop is looking pretty nice. Both store their calendars in standard iCal .ics files, but I need to come up with a decent way to keep them in sync. Obviously I could cron something from Linux, but I don’t really have a good way to bring Windows into the picture. Not to mention the fact that it would just be a disaster trying to figure out which version is newer. Maybe I just need to find a new program that will automatically import/export to a remote location on open/close? Suggestions anyone?