DynSite for Windows Description:

DynSite automatically updates your dynamic IP address each 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.org, where myhost is a name of your choice). Since your host name never changes it makes accessing your servers much easier than using your IP address which changes each time you reconnect. This is also useful when you want to remotely control your PC.