Am I destroying my bulbs?

An update to the CFL / LED Conversation. THIS comment at Treehugger made me realize that I may end up burning out my new LED bulbs that are currently on a dimming circuit in my son's room. I was under the impression that when you turned down the dimmer switch you were applying less current to the bulbs which is what I *thought* they need in order to "dim". I guess turning on fewer of the bulbs in the array is the better option, but I know these bulbs weren't wired that way (they would have cost a lot more than they did!). I've seen some DC flashlights that had circuits that were designed this way (Princeton Tech) and I know that LRI (the folks who make the Photon Micro lights) uses Pulse Width Modulation in their Photon Freedom line of lights to "dim" the LED's. In a household application, I'm not sure if this would be distracting (or even possible) to walk around under (I have recessed ceiling cans in most of the rooms in my house). Any electrical engineer types want to chime in here?