From Orvonton Products:
Stealth Ping is a handy little program that keeps you from being logged off by your ISP for Internet inactivity. Stealth Ping keeps you connected by sending packets of data at random or at fixed intervals to simulate actual Internet activity. Unlike other connection products that only ping the ISP at fixed intervals, Stealth Ping uses an algorithm to vary the size and the interval of the data packets sent. So, in Stealth mode, the ISP "thinks" the packets it is receiving are normal Internet traffic. As a result, the inactivity timer running on your account will be reset every 15 to 100 seconds. Simple to install, Stealth Ping has an easy-to-use graphical interface and occupies less than 38K of disk space.