So if I do a neighborhood newsletter once that I place on all my neighbors doors, that is not press? I would think that would fall under the freedom of press clause, but I would not be considered part of the media.
A newsletter would qualify for Freedom of the Press as you are distributing news, opinions or other information to a group of people. In that one specific case, you would be considered part of the media.
Being written versus spoken does not matter. For example, the Fox News channel enjoys Freedom of the Press protections for their TV newscasts even if they never write a single word.
The rise of blogs and internet sites like Free Republic and Drudge have brought new debate to what constitutes being a member of the "press".
A personal letter, however, would be Freedom of Speech.