If you are moving your site to a new server and want to view your site before you've switched the DNS you can do this by editing the hosts file in windows XP pro.
1) Open the file c:\windows\system32\drivers\etc\hosts
2) Add the IP of the new server and the URL. When we moved realestatewebmasters.com here was the entry in my hosts file.
Then I closed all my browser windows and opened realestatewebmasters.com to verify that the move was successful.
Once verified I added removed that line from the hosts file.