On Ubuntu 12.04 I would like to have the following: The computer is running but no user is logged in. So the OS is displaying the login screen. In this screen how can I enable remote login to any account? Preferrably with a GUI (i.e. see the whole desktop and everything, not only a shell like ssh would do).

So far I have been able to offer remote access using vino while being I logged in locally. But when I log out, the vino process is gone as well, so remote access is not available anymore.

Furthermore I have observed on my personal laptop that internet access using WLAN is not possible in the login screen due to missing priviliges. I'm not sure if it helps that the computer in question has a fixed IP address and is connected via LAN cable. If I remember correctly, I think I saw the 'connected' icon during login screen. Not 100% sure however. (Can't check this atm, since I don't have access to the computer till weekend).

How would I do this?