With the knowledge that I’ll be moving to the T-Mobile G1 in the near future, I started thinking about my contact list. Yeah, the one I have in Outlook that I sync to my current Windows Mobile phone. But wait, there’s no sync client for Android phones.

However, in the case of the T-Mobile G1, it will sync it’s contact list with my Gmail Contacts over the 3G connection. Ok, I can live with that – it actually works out better in the end. More on that later. With that realization, I started thinking about how best to edit and update all those contacts I have in Gmail.

For a long time I had looked for some kind of utility to sync from Outlook to Gmail Contacts. I was hopeful when early last year Google themselves released a Outlook to Gmail Calendar sync tool. Alas there was no contact sync utility, just some API extensions to make it possible.

Since I’ve been playing evaluating Thunderbird as a replacement for Outlook on and off for a year or so, it occurred to me that there may be a way to sync Gmail items to Thunderbird via Add-Ons. Sure enough, they exist. With a Gmail Contact Add-On and a Gmail Calendar Add-On, I’m able to edit and update these times fast and easy via a great offline client.

The great part of all this is that because the G1 automatically syncs Gmail, Contacts and Calendar – all my PIM data will now effortlessly be in sync from PC to Web to Mobile. No matter where I go to send an email, make a call, or view my schedule, it will always be in sync.

Do you know of any interesting Google or Gmail related Add-Ons for Thunderbird that would make it even better? Let us know what you find that works!

Now to just wait for the G1 to be delivered…