I was doing a search for an external 1000 watt Light Dimmer Switch & I came across this ad.
Says you can use the fan speed controller as a dimmer. The reviews on it says it only dims down to about 25%; but who needs to go any lower then that ... right? Haven't tried it yet but will some time today. This will be a great cheap way to add a dimmer to any light if it works.
High Capacity Dimmer Control
A portable and very inexpensive solution to your dimming control problems! Most Pro Light Kits usually don't have a built in dimmer option and require many moves, adjustments, and frustrating small tasks to get light levels correct.
www.markertek.com