A new and really cool feature in MOSS 2007 and WSS 3.0 that my team here at Vorsite and I are very happy about is that now you can quickly and easily change the name of a server running MOSS or WSS 3.0 after installation has taken place and site collections have been created. Before with SPS 2003 it was a near impossible challenge but now in MOSS you can use a nifty stsadm.exe command to do most of the heavy lifting.
Here are the steps to do this in MOSS 2007 or WSS 3.0:
First: Change each alternate access mapping for your MOSS/WSS deployment in Central Administration
Second: Use stsadm.exe to invoke the “renameserver” command option
stsadm -o renameserver -newservername <newname> -oldservername <oldname>
Third: Rename your Server via Change Name Operation in Windows Server 2003
Now your server is renamed and all MOSS/WSS web applications and site collections should work perfectly fine.
This article is from http://www.jjfblog.com. Also you can get a Chinese version from http://blog.joycode.com