WinGuardian
Looks harmless in the running applications list, or is it hidden? I forget.
Option of output to a text file or email
Activated by keystroke combination of your choice
Records title bar of window keystrokes were sent to.
Records any programs that are opened/run.
Option of automatically running on startup.
Will be noticed by some spyware scans, needs to be excluded explicity
It's not free.
I've used it before.