DynamIP is a free Internet utility that combines lots of functionality in one nifty application:

You can even install DynamIP as an NT Service!

Here's the wordy version:

DynamIP is a completely free multi-functional internet utility. Its major features include a timer-/traffic-controlled DUN/RAS dialer, a timer-controlled and event-driven WEBcam utility, an IP chat engine (like using IRC, but without the need for an IRC server), IP scanning (especially useful for posting your dynamic IP address to web pages), background e-mail monitor (periodically checks for new mail on up to 5 different mailboxes), a WEBchat feature (allows chat between DynamIP users and browser users), integrated Dynamic IP Server (DIPS) support, and a time synchronization tool (synchronizes your PC clock with the correct Internet time by connecting with an NTP server). DynamIP's IP scanning feature is most useful for those whose Internet address frequently changes (especially for those without
dedicated lines). DynamIP will post your dynamic address to web pages and then automatically upload those files via FTP. The client also supports up to five connections for those with multiple internet providers or web sites to maintain. With DynamIP's chat feature, you can input a range of IP addresses to scan and the client will find any users within those numbers that are also using DynamIP. You can then send messages to all of these users or to a specific user.

DynamIP's newest feature, Dynamic IP Server (DIPS) support, allows users to run a Web Server with a fixed URL from your own computer even when you have a dynamically assigned IP addresss. DIPS keeps track of your IP address in real time and makes it possible for others to access your web information by following ordinary web links. This is especially useful if you want to run your own WEBcam server from your computer. DynamIP presents a solid selection of configurable options for each of its features and does so with an intuitive, easy to use interface.

Additional features include its ability to run minimized in the Windows 9x/NT icon tray in order to reduce taskbar clutter, tracking capabilities of all events and actions in a log file for your later use, event notification (customizable sounds to alert you when a new event occurs), AutoSense (keeps DynamIP fron running mail checks when you're not connected), and AutoRefresh (gets new IP addresses for you after a disconnect or redial). DynamIP is a multi-threaded 32-bit application that will only run on Windows 9x/NT platforms.

And DynamIP does all of the above things with minimal drag on your CPU (however, it's somewhat of a memory hog) and you can have it running at all times, whether you're logged on to the Internet or not.

Most importantly, however, DynamIP is Freeware (i.e. no time limits, no nag screens, no ads, just plain fun).