INADYN is a free, multi-platform dynamic DNS update client. It gives the
possibility to have your own fixed hostname registered on the Internet,
although your IP might be changing. It checks periodically whether the IP
address stored by the DNS server is the real current IP address of the machine
that is running INADYN.

INADYN supports the following dynamic DNS services:
 - dyndns.org (in all three flavors: dynamic, static, custom)
 - freedns.afraid.org
 - no-ip.com
 - zoneedit.com

WWW: http://www.inatech.eu/inadyn/