Wouldn't it be nice to have a hot key in Byobu that would send a command to multiple splits (or windows?This feature was added and is available in Byobu 5.73 and newer (in Ubuntu 14.04 and newer, and available in the Byobu PPA for older Ubuntu releases).
I actually use this feature all the time, to update packages across multiple computers. Of course, Landscape is a fantastic way to do this as well. But if you don't have access to Landscape, you can always do this very simply with Byobu!
Create some splits, using Ctrl-F2 and Shift-F2, and in each split, ssh into a target Ubuntu (or Debian) machine.
Now, use Shift-F9 to open up the purple prompt at the bottom of your screen. Here, you enter the command you want to run on each split. First, you might want to run:
This will prompt you for your password, if you don't already have root or sudo access. You might need to use Shift-Up, Shift-Down, Shift-Left, Shift-Right to move around your splits, and enter passwords.
Now, update your package lists:
sudo apt-get update
And now, apply your updates:
sudo apt-get dist-upgrade
Here's a video to demonstrate!
In a related note, another user-requested feature has been added, to simultaneously synchronize this behavior among all splits. You'll need the latest version of Byobu, 5.87, which will be in Ubuntu 14.10 (Utopic). Here, you'll press Alt-F9 and just start typing! Another demonstration video here...