If you want to connect to Ubuntu machine through remote desktop, xrdp can be used.Below are the steps.
Install xrdp
sudo apt-get install xrdp
Configure xrdp for user e.g sysadmin.Change directory to sysadmin’s home.
sysadmin@server02:~$ cp .Xauthority .xsession
sysadmin@server02:~$ > .xsession
Run the command below to add the entry.
sysadmin@server02:~$ echo "gnome-session --session=ubuntu-2d" > .xsession
Restart xrdp
sudo service xrdp restart
Now you should be able to connect through rdp clients such as krdc.
NOTE: The steps mentioned above does not work with ubuntu 12.10.you need to install xfce4 desktop in higher versions.
palatana 