gpg Error from the launchpad repositories when running apt-get update or synaptic

  Recently I started to get some errors when trying to update my system.  I received the error

W: GPG error: http://ppa.launchpad.net intrepid Release: The following signatures couldn't be verified because
the public key is not available: NO_PUBKEY 28A8205077558DD0

  So, I wrote a script to download and apply the keys. Just highlight and copy the number following the "NO_PUBKEY".

  Download my script and make it executable.

chmod +x update-gpg-keys

  Then run my script and pass the key number to the script like so

./update-gpg-keys 28A8205077558DD0

  Now you can run apt-get update or run synaptic without errors.