Legal Weather Sources?

Aside from a call or visit to an FSS, or DUATS, are there any other
"legal" sources from which a pilot is allowed to obtain weather reports?
I'm not talking about what's actually *useful* here...hell, sometimes
the weather channel is the most useful thing out there...I'm interested
in what's *legal*. What weather sources *must* we consult as pilots
from an FAA standpoint to prove that we have "become familiar with
all available information concerning that flight", as per FAR 91.103?

There are a whole slew of web sites offering "aviation weather" products,
such as:

http://adds.aviationweather.noaa.gov/
http://weather.unisys.com/aviation/
http://www.weathertap.com/
http://www.flightbrief.com/

How many (if any) of these are a "legal" source of pre-flight weather
information as stipulated by FAR 91.103, which states:

Sec. 91.103 - Preflight action.

Each pilot in command shall, before beginning a flight, become familiar with
all available information concerning that flight. This information must
include --

(a) For a flight under IFR or a flight not in the vicinity of an airport,
weather reports and forecasts, fuel requirements, alternatives available if
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
the planned flight cannot be completed, and any known traffic delays of which
the pilot in command has been advised by ATC



-- Dane