Free DNS When You Need It

Dyn’s legendary free DNS service allows you to create a hostname that points to your home or office IP address, providing a easy URL for you to remember anywhere you have internet access.

Dyn also provides update mechanisms for making hostnames work with your dynamic IP address, delivery of your DNS records to five DNS servers in five Tier 1 bandwidth datacenters around the world, fast propagation/reliable static IP caching for DNS TTL values and more.

Website: http://dyn.com/dns/dyndns-free/