Rotating menu

i want to make this menu which a part of it rotates. I have a circle with text besides it. This are the buttons. On this circle i have some kinda thing which points the button of where the users mouse is on. So each time the users chooses anothe button, the pointer has to rotate to that button. If there is no mouseover or anything, the pointer has to point the button on where the user is on the site (so in home the point has to point to home button)
anybody who can help me?