Launch Effect is a fully free WordPress theme with a very simple approach. The theme is a one-page design that goes at the front of your new WordPress install, letting your visitors get a sneak peak for what you are releasing and allowing them to sign up for more information over email once it is here.
These interest-sparking intro screens are a very good way of promoting your unreleased product or website and gathering a user base even before you have the final release product available.