The skincheat is a little easter egg in Winamp. To activate
it type Nullsoft (with Esc after each "l" to close the dialog) while the Winamp window is active. Now the title bar of the main window changes into another. What appears now the skinner decides. Typically it is a text, short information about the skinner or something else.
If you do the skincheat and the Winamp default skin is
loaded this text appears: "it really whips the llamas
ass". Try this with your other skins.