Syncing contacts between Mac, Nokia E51 and iPod touch

Solution 1:

You can use Google Sync to sync all of your devices together.

Solution 2:

You should check out NuevaSync for supporting your iPod and phone

Solution 3:

As a previous poster said, use http://nuevasync.com to turn your Google Contacts into an Microsoft Exchange service. Then connect the Nuevasync Service from your iPod Touch and your E51.

Your Mac is a different story. See also a question I have asked here: Google Contacts and Mac OS X Address Book

Your best best is to enable Google Contacts sync form Mac Address Book and live with the limitations of that, unless someone comes up with something clever. Snow Leopard will enable you to hook up Nuevasync to the OS itself.