Ubuntu server and Gnome desktop

[Krapacs Ambrose]

I installed Ubuntu server (8.10) and while I was troubleshooting some  
configuration problems I installed the desktop (apt-get install ubuntu- 
desktop). Now when I boot up the server it boots directly into the  
desktop rather than to the command prompt like it did before I  
installed the desktop. Is it possible to configure my machine to boot  
to the command prompt by default and when/if I need the desktop I can  
initiate it from the command line?