I want to capture video tutorials, I already did, but I still miss a tool that automatically displays the pressed keys and mouse buttons.

Question 1:
Is there already an inexpensive tool somewhere in the net?
(the newest version of Camtasia is quite expensive)

Question 2:
Is there a way to program such a tool without much effort?
(in any language)

Question 3:
Is it possible to program such a tool with Lite-C without knowing much about the window API and such?