If the Shockwave program above does not load, download and install the plug-in.

Use the tools above to adjust your mobile's size, speed, orbit, and balance.
Click the red square for a menu of 60 shapes and colors.
Switch to TOP VIEW and turn on TRAILS to create spirographic patterns as the mobile spins.
 
For best results, run your PC or Macintosh web browser in 32-bit mode.

If your Mac is running Lion or Mountain Lion, or if you are experiencing plug-in problems,
you may prefer using the downloadable desktop application of Mobile.

Credits