The Clock Screensaver (Posted in Software | Screensavers) was completed in just 1 evening (around 3 hours) using the screensaver template and tutorial previously posted.  Most of that was creating the images for the textures that are used.  Check it out, it uses OpenGL and should run well on even low specification systems.  It uses system ticks to calculate rotation ammounts so it should be reasonably smooth at even low framerates.