Dynsite is described as 'DynSite automatically updates your dynamic IP address every time it changes on one or many dynamic DNS services or by email. This allows anyone to connect to the servers (Web, FTP, NNTP, etc.) running on your own computer using a fully qualified domain name (e.g. myhost.dyndns'. There are four alternatives to Dynsite for Windows, Linux and Mac. The best alternative is OpenDNS Updater, which is free. Other great apps like Dynsite are DirectUpdate (Paid), Marcs Updater (Free) and DDNS Updater (Free).
OpenDNS recommends that you use our client-side software to keep your dynamic IP updated for your network. The OpenDNS Updater will run in your system tray and send updates to your account whenever your IP address changes.
Your router doesn't support DynDNS, OpenDNS or DNS-O-Matic by default or is limited in number of dynamic DNS services? You can use this simple client to send IP changes to your dynamic account automatically.