If your computer is connected to the internet, you can run ssh -X hostname where hostname is the name of the computer that you want to log into. The -X flag enables X forwarding. You can then run X applications within that ssh window and they will display on your local desktop. For further information, such as getting this to work on the Windows operating system, see the SSH X Forwarding documentation page.
VNC is also available, although we generally discourage its use when X forwarding is an option.