This is a very simple "stay connected" program to keep your ISP from signing you off after a certain amount of minutes of inactivity. I'm not sure if it will work with all ISPs, but it worked with a local dial-up ISP I used to have (now I have broadband), so maybe it'll work with yours...
Anyways, what this program actually does is ping a random website from a list of websites that you can define (these should be well-known, reliable websites that are almost never down.) It pings a random website from the website list at a random interval between (x / 8) and x minutes, where x is a configurable value (in minutes) that the user can set, to "simulate" web surfing. In other words, if you have x set to 8, it will ping a random website from your website list between 1 and 8 minutes from the last time a site was pinged (pung?) or from when you started the program.
Even though this is technically a DOS program, under Windows it will still run even if you task switch to another program, so you can just minimize it to the taskbar while you're surfing the Web or whatever and let it do its "stay connected" actions (i.e. pinging websites at random intervals). (If it stops running after you task switch to another program, go into the property sheets for the program and under the Misc tab, make sure the "Always suspend" checkbox is unchecked.)
The Simplest? Stay Connected Program doing its "stay connected" actions
Click here to download the zip file containing the program (47k), and unzip it to whatever directory you'd like to install it in. Source code is included in the zip file. You can run this program under pure DOS as long as you have CWSDPMI, but I can't really see the point in running it under pure DOS since it's a single-tasking OS and you need multi-tasking to browse the Web and use this program at the same time. (Of course, some people say Micro$oft Winblow$ isn't really multitasking either, but that's a different issue...)