Liquify your Mac OS X screen with Fluid2

Fluid2 is a realtime fluid-dynamics model and rendering engine that uses OpenGL to create the effect of flowing liquid on your screen. Each launch of Fluid brings a completely new experience and never-before-seen images based on settings you make to colors, rendering styles, resolution, and many more options via the preferences sheet. The current v2.0 adds 3D surfaces, reflections, shadows, streaklines, contour lines, and particle systems. Fluid is enhanced to take advantage of Altivec and multiple processors. More info and freeware download link here.