You can also host sites without domain names (the so-called stop-gap domains). When you create a stopgap domain, you get no DNS zone, and you cannot use e-mail service. However, you will be able to access and manage your site using the instant domain alias you get at signup.
Stopgap domains support web site management and FTP services. Also, you can have IP-only access if you get a dedicated IP.
To create a stopgap domain, just click the Submit button in the Stopgap domain registration form: