Just a hurried note, will add more details soon, but this should have the relevant info…

On Nokia, set up, Mail For Exchange (from Ovi Store), and then visit this link on google:

Google Sync for Nokia S60 to link your phone to your calendar. I’ve set up the sync time as once every 12 hours, as this is sufficient for my purposes.

Then on Thunderbird, install the Google Calendar Provider Addon (simplest way is in Thunderbird, go to Tools -> Addons -> and enter this in the search box, to install directly). This allows you to connect to the Google Calendar from thunderbird.

Instead of a TODO list, I create an “Event” for each TODO item, and this allows me to set up a reminder and a date for each item, and also syncs across Thunderbird, Google Calendar and my phone!