Official Answers
I apologize about the repo key. There is a key, but I forgot to post it. You can get it here: http://www.thinkgos.com/files/gos_repo_key.asc
Add the following deb lines to sources.list to use our repository with Ubuntu:
deb http://packages.thinkgos.com/gos/ painful main
deb-src http://packages.thinkgos.com/gos/ painful main
Try to be nice to it, we are still in the process of moving servers and our current one has been under quite a bit of stress so far :)
Currently there is a greenos-desktop package in our repository, but it will not give you the complete experience. We are still hammering out the packaging, but eventually this will be easier to do. Also, we do not use network-manager so if you do install the greenos-desktop, network-manager will be replaced by the network configuration tools we are using.