Take a look at System Surveillance Pro 5.5:
http://www.download.com/System-Surveillance-Pro/3000-2162_4-10332800.html?cdlPid=10790483
"This snooping utility provides almost all the features essential for monitoring a PC, but we were especially impressed with its stealthiness. System Surveillance Pro logs keystrokes, IM chats, applications used, and Web sites visited, and can capture screenshots at user-defined periodic intervals."
Curtis
TVover.net