Yes, the 705.

Go to the product page on garmin.com, click on "Updates & Downloads" on the right, then download the WebUpdater app. That application works for all the fitness units (maybe all their units, I don't know). You can also download updates to Training Center from the same page.

On the Mac, you have to actually run the WebUpdater app periodically (with the GPS connected to the computer). DH's Windows box automatically updates his car GPS, but as I said, I'm not sure if that's the same WebUpdater.