Meta Backup is a script that creates a meta .deb package which depends on all the applications you've installed on your computer along with all the PPAs - you can then use this .deb to install everything from your computer on other computers. Of course, your settings will not be saved in the .deb so it should not be used as a backup solution, but only as an easy way to get a similar setup on multiple computers.
We've actually wrote about this a while back, but using commands for generating a list of all installed packages and so on. So the method in this post should be a lot easier to use (after downloading and installing the .deb, you only need 2 clicks to create the new meta .deb).
Usage: download Meta Backup, install it, then go to Applications > Other > Meta Backup. When running it, a Zenity dialog box will pop-up, asking you if you've enabled extra repositories on your system - select yes or no (most probably "yes", right?) and that's it. You should now have a new .deb file in your home folder, called "my-meta-backup.deb". Installing this .deb on another computer will add all the PPAs and install all the applications from the first computer.
Update1 : this doesn't work as it should if you use PPAs. It should firstly install a .deb that adds the PPAs and then install a second deb which has all your applications as dependencies (or use a different way of installing the dependencies as the PPAs need to be added before installing the dependencies, not in the same time as that obviously doesn't work). Hopefully it will be updated but until then, I've modified Meta Backup to do this - DOWNLOAD my version. This will create 2 .deb files: one with the repositories (my-meta-repositories.deb) which you need to install first, then run "sudo apt-get update" and then install the second .deb (my-meta-backup.deb).
And a final note (thanks to _khAttAm_!): this will fail if there is package (or more) in Synaptic in Origin>Local (and if any version of that package is not available in any of the PPAs to be exact) in the source machine.
Update 2: _khAttAm_ created a script that does this better (but does not create a .deb, you'll have to run the script). See his post: [HOWTO] Install all the packages installed in one Ubuntu Installation to another
And a final note (thanks to _khAttAm_!): this will fail if there is package (or more) in Synaptic in Origin>Local (and if any version of that package is not available in any of the PPAs to be exact) in the source machine.
Update 2: _khAttAm_ created a script that does this better (but does not create a .deb, you'll have to run the script). See his post: [HOWTO] Install all the packages installed in one Ubuntu Installation to another