I dropped my 580EX onto a tile floor.
The red lens covering the auto focus sensors is all that broke. I called 1-800-OK Canon at about 3pm and was able to order it. I had it by 3pm the next day ! It cost $15usd for that small piece of plastic but was cheaper than sending the flash out for repair and wondering if I would have it back in time for a night football game on Friday.
Be careful with your gear