HDTiVo has discovered a method to download Amazon Unbox videos to multiple TiVos simultaneously (using XP and IE7). No telling why you’d want to do this (unless you have kids) since the license and content are transferable, but like many hacks that isn’t the point.
After clicking the download button on the downloads page with the list of your unbox videos, you get a thumbnail page with a drop down box to choose the device and click another download button.
After doing that, a confirm page comes up (for me in a new tab) which I close. I am left with the prior thumbnail page that still has the drop down box. I can then choose another device to download to and click download…
… repeat as many times as you like.