Uniis - Offers name registration, including the .US domain. - http://www.uniis.com/
USDomainRegistrar.com - Free domain name registry service for .com, .net, .org. Also assisted registration by phone or email. With a glossary of domain name terms and discount off of Internic filing fee. - http://usdomainregistrar.com/
USP Networks - British-based domain name registration and web hosting service. - http://www.usp.net/
Universal Domains - Domain name registration, trademark check, unregistered domains and name appraisals. - http://www.universaldomains.net/
UKnames.net - Site offers domain name registration service for UK and US names. - http://www.uknames.net/