It is possible to acquire ownership of a trademark by filing an "intent-to-use" (ITU) trademark application with the U.S. Patent and Trademark Office (PTO) before actually starting to use the domain name. The applicant must start using the domain name within the required time limits -- six months to three years after the PTO approves the trademark, depending on whether the applicant seeks and pays for extensions of time. The filing date of this application will be considered the date of first use of the trademark as long as the applicant actually uses the trademark within the required time limits. For more information about trademark registration, see How Federal Trademark Registration Works.
To learn about the most current information on domain names, changes to trademark statutes and case law, and the latest registration processes, get Trademark: Legal Care for Your Business & Product Name, by Stephen Elias and Richard Stim (Nolo).