Well, one way to "trick" keylogger is to have for example a text editor open; if you want to enter a sensitive information, you begin by typing some letters, then you switch to the text editor (using the mouse, not something like Alt+Tab, just to be sure), type a couple of "random" letters there, switch back and continue entering your sensitive information, than go back to the text editor, etc. It's long and painful, but if well done it could make finding the "sensitive information" more difficult. Of course, it's not bulletproof. Especially if the keylogger is "application/window specific" (do they exist?), i.e. it doesn't log all the entered keys in the same file.
