I'm using a USB to boot Tails currently.

I'm looking for a way to not having to download new versions of Tails to my hard drive for every update. Is there a way upgrade Tails without having the download the new version to my hard drive first?

This is not currently possible. ?incremental upgrades will support this usecase to some extent.
Comment by Tails Mon 26 Nov 2012 11:35:03 AM CET