Amazon Web Services now has a DNS service in beta.
Amazon Route 53, is a Domain Name System (DNS) web service that can be used with AWS services or as an alternative to other DNS services.
AWS' new service uses a global network of DNS servers that is designed to automatically respond from the optimal network location, resulting in low DNS query latency for end users.
The service cost is $1.00 per hosted zone / month plus $0.50 per million queries for the first 1 Billion queries / month and $0.25 per million queries for over 1 Billion queries / month.
More info at Amazon Route 53.