How do you keep processing keystrokes while the app is minimized or in the systray?

It depends how your getting keystrokes...

With DirectX (For games usually) you have to capture the device in DD_NONEXCLUSIVE or DD_FOREGROUND mode.
If you use Exclusive mode it won''t allow anybody else to use the keyboard.

I believe if the app is not active, you don''t get the Windows Messages, so I''d use one of the API calls like "GetAsyncKeyState" or "GetKeyboardState", which both perform a little different, I believe the first one returns the state (UP or Down) of the key you ask for, the second returns a list of the states of the 256 virtual keys, so it''ll tell you when the hit some weird characters like Alt-0186 which happens to be º the degree sign!

Anyhow have fun!
See ya,
Ben

P.S. Yah once in school we were making nauty programs and we used GetAsyncKeyState to make a keylogger for passwords and stuff. So I know it works.... Just don''t tell anyone I''m a KiLlER HaKER!