Quote Originally Posted by blueclue7
I think that properly it should be the "how does ONE say"; as I believe that один / одна is often dropped in a sentence -- (of course, ты / вы is dropped as well, but the verb ending ordinarily gives us the proper tense beyond the infinitive).
Right. And since Russian verbs' and adjectives' endings often give sufficient clues on what or who they relate to, Russian sentences often lack a subject. Consider the following dialogue:

-- Принтер не работает.
-- Новый или старый?

Here, the only masculine noun in the first sentence is "принтер", so it's pretty easy to guess what "старый" and "новый" relate to. You don't actually drop "один", you just don't need it. (And you'd really confuse native Russian speakers using "один" as you would use "one" in "Which one, the new one or the old one?")

Now, with "Как сказать" we have a slightly different situation. Here, the speaker doesn't care who's going to say this or that. The speaker's interested in the way something is generally said by anybody willing to say it. Different languages use different means to stress the fact that the speaker is interested in action itself and couldn't care less about who or what performs it. In French, one would use a special "impersonal pronoun". In English, one absolutely has to use some subject (a "you" that means no particular person or persons in such contexts, or "one") no matter what. In Russian, you simply drop the subject altogether and use an impersonal sentence:

Как сказать "this weather sucks"?
Как отсюда позвонить в город?
etc.

So both "How does one say?" and "How do you say?" are good translations for "Как сказать". You just have to insert some subject (="Просто необходимо вставить подлежащее"="One just has to insert a subject") the Russian phrase happily lacks altogether.