In response to this very old question by myself and the ever looming threat of total Internet control by the world's superpowers, I have created a free DDNS service in New Zealand.

Here is the blog describing how, where, when and the terms of use: http://www.arcainsula.co.nz/2011/01/free-dynamic-dns/

Here is the login/register page: https://ddns.arcainsula.co.nz/

First off, no losers or pirates. If we find the service is being used to dole out poor taste, we will delete the account and reserve the domain names forever.

Working email address is required and you accept one email per month from us with information about our company as well as usage stats, service availability updates etc.

Limit of 10 names per email.

The client allows you to decide how the names are resolved - fixed, internal or LAN connection or web based.

Works well with Windows and Linux.

Redundant service with good backup and duty cycle.

Have fun.