I've been using a Stainless Steel egg timer that I bought off Amazon.com as a simple panning device for my time lapse sequences. The egg timer will rotate a full 360 degrees in one hour. I thought that having other options would be nice, and found a lawn sprinkler timer at the Home Depot that rotates 360 degrees in 2 hours. Basically, the rotation is half as fast. I bought one, and immediately dis-assembled it to see how it worked. The actual timer is very similar to the egg timer, so the gear ratio must just be different. I added a 1/4" screw, which is a standard size for cameras, to the top. Then I drilled another hole in the bottom to add a 1/4" screw and coupler, which can attach to any standard tri-pod fitting. I sawed the hose fittings off, and used a Dremel tool to smooth out the plastic where the fittings were removed. The lawn sprinkler seems more stable than the egg timer, and I'll be testing it out soon to see the differences in panning speed.
I'll post a video when I get a chance to test the new lawn sprinkler panning device.