xProDDNS!

Free DNS, Dynamic DNS, Static DNS services; 5 free shared hostnames, use anywhere; Unlimited number of domains per account (yes really);Free subdomain hosting, free domain hosting, free backup dns, reverse IPv6 DNS hosting (forward/reverse);Free URL redirection [web forwarding];20 free subdomains per domain, use on your own domains onlyINSTANTLY point yourname.afraid.org or yourname.com to any IP or URL;Dynamic DNS supported, several clients for Win32 and UNIX availableCurrently 86,232 other domains besides afraid.org in our shared domain pool;Round robin DNS supported (Multiple IP addresses for 1 hostname);IPv6 forward AND reverse (both .int and .arpa) supported. »

Duck DNS free dynamic DNS hosted on Amazon EC2.Duck DNS is a free service which will point a DNS (sub domains of duckdns.org) to an IP of your choice.

DtDNS provides DNS hosting and related services to everyone from home users to hosting firms with hundreds of domain names. Dynamic DNS is supported on all services.