You can use the Fantastico scripts while your domain is still being registered or changing it's DNS to the Green Geeks servers. It is far easier to wait the 24-48 hours for your domain to propagate but if you cannot wait this is what you want to do.

Pick out the script you want to try out, and install it. Please remember the folder you created, and use this address to view, and access your scripts: http://ipaddress/~username/Foldername/

To obtain the correct IP address please use the numbered IP address which you received in your account welcome login email: an example of what this would look like is  194.20.193.30

For your ~username, provide the "~" symbol, and your username from your welcome email.

As for the Foldername, enter the destination folder you created when you installed the script.

You can also try to stage your web site without switching the DNS or waiting for it. Follow this blog post:

http://blog.greengeeks.com/2009/09/26/see-stage-your-website-before-switching-your-dns/

Please keep in mind that Green Geeks technical team does not actively support or troubleshoot these scripts. You will need to refer to the user manuals, websites and forums for the various scripts in the Fantastico script installer.