You're not going to come on here with something like "zomg you use google so you use Linux without knowing it!" are you?
I think a better question would be to ask people if they knowingly use Linux every day. Server's don't really count, neither do technically phones (Unless you have a n900 :P) or tivo, since these are appliances. In these cases you're not using Linux so much as you're using the appliance.