SimpleActivityLogger is a Windows service that records the following events to the Windows Event Log:
System Startup & Shutdown;
Power events (suspend, hibernate, resume);
User Logon & Logoff;
Console Lock & Unlock;
Screen Saver start & stop;
Monitor Power on & off;
Fast User Switch.
There is also a small GUI application that allows the user to view the event log and append user events to it.
SimpleActivityLogger is most useful for people who need to track their computer usage during the course of a day, perhaps for billing / timesheet purposes.
It is also useful for tracking the usage of a shared computer. However, it is not a covert 'spy' program and makes no attempt to disguise itself.