Some electronic timers and photocells contain parts that are incompatible with compact fluorescent light bulbs; using these bulbs in incompatible products will result in a shorter light bulb life. To find out if an electronic timer or photocell is compatible with compact fluorescent bulbs, check with the manufacturer of the timer or photocell.
You should not use a dimmer on flourescent bulbs as it can cause flickering and shorten the life of the bulb.
Here is a link to GE, a big manufacturer. They have a faq on cfl's.GE Consumer & Industrial Lighting: Ask Us: FAQs - Compact Fluorescent Light Bulbs
HHHmmmmm- I've been using the same Lights of America 65 watt floros for 5 years now in my veg box with the same bulbs all 5 years. (these are the same ones advertised on ebay as being equal to a 500watt light) I think they mean 500 watt incandescent on ebay which doesn't help us but they don't say incandescent so most think HID's. I've been using a timer the whole time so I guess I got lucky with a timer that is compatible. Just a couple of cheap $20.00 digitals from OSH (orchard supply hardware). Even if I did hurt the bulb at $8.00 each it's not too expensive to replace them and I know they last 5 years or more. These have a external electronic ballast as well which might have something to do with them lasting and working.
Here is a link to the floros I use. I got mine at cosco for $20.00.