Landscapers, Florists and homeowners work with 'bulbs'.
Electricians work with lamps.
This is not verified, but I was recently told by one of the counter guys in a supply house (who claims to have taken a class about it) that when we install it into a fixture (fluorescent, HID, etc) its called a "lamp". But when installed into a table lamp or the like, it's called a "light bulb"
Now, I have not even thought about verifying this, but it seems to fit into the conversation.
