Note to Builderguy and Atticous:
A dynamic name service like DynDNS is not the same as a DNS server - more like different sides of the same coin. A DNS server will relate a single host name to an IP address. Every ISP provides DNS services otherwise you couldn't access the Internet with names.
A Dynamic DNS service like DynDNS is a separate service where they keep track of changing IP address and relate that to a static hostname they provide for you.
DNS services are free from your ISP or within your company. Dynamic DNS is typically a fee-based service.