DANNY - Is there ever a reason to fast for more that the "standard" 2 meals or, 24 hours? More specifically... are there cases of extreme health problems(cancer, severe emotional upsets, etc.), that would be better served with a 48, or 72 hour fast? Can we actually get "more" prepared with "more" time? You know... "these come out only by fasting, and prayer..."

JOEL - How long you fast is between you and God and your doctor. The Church recommends two meals as a general rule, because it is what most people can tolerate without risk to the health.
President Joseph F. Smith pointed out that fasting “is a duty from which [we] cannot escape; but let it be remembered that the observance of the fast day by abstaining twenty-four hours from food and drink is not an absolute rule, … but it is left with the people as a matter of conscience, to exercise wisdom and discretion.” (Gospel Doctrine, 5th edition, Salt Lake City: Deseret Book Company, 1939, page 244).
The inadvisability of excessive fasting was explained a June 1972 Priesthood Bulletin:

“We are informed that some … engage in rather lengthy fasting. It is not advisable that they do this. If there is a special matter for which they should fast, if theywould fast one day and then go to the Lord humbly and ask for his blessings, that should suffice.” (First Presidency, 1972)

Joseph F. Smith counseled:

“Many are subject to weakness, others are delicate in health, and others have nursing babies; of such it should not be required to fast. Neither should parents compel their little children to fast.” (Gospel Doctrine, p. 244.)

More important than how long a fast is, is having a good reason to fast; properly preparing for the fast; and behaving in such a way as to invite the spirit during the fast. During the fast one should frequently contemplate and meditate on the reason for the fast; achieve a oneness in purpose and spirit with God; and maintain a quiet, humble, and cheerful conduct appropriate for one seeking blessings or spiritual enlightenment (Matt. 6:16-18; 3 Ne. 13:16-18), and offer a prayer of gratitude when ending the fast. If it is done correctly there should be no reason to fast much beyond 24 hrs.

DANNY - Here's another that I need help with... soon if possible... "forty days, and forty nights"... was it really forty days? I have a note in my scriptures at Matthew 4:2 that says that "forty days, and forty nights" is Hebrew for a long time, or certain period of time. I can't identify where that note comes from. Your feelings please...

JOEL - In the Bible, next to the number seven, the number forty occurs most frequently.
It was the number of days God made it rain. (Genesis 7:4)
It was the number of years Israel ate manna (Exodus 16: 35)
It was the number of days Moses was with God in the mountain (Exodus 34:28)
It was the number of years the children of Israel wandered in the wilderness; (Numbers 14:33)
It was the number of days Christ fasted before beginning His ministry. (Matthew 4:2)
The risen Lord spent forty days with His apostles in Israel (Acts 1:1-3)
and many other places throughout the scriptures.

Sometimes when it says forty it means forty, other times Bible scholars believe it is used as just a round number that was symbolically assigned to give a value that represented "many" or "some", but it's not always easy to tell which is which.
According to scripture scholars George Reynolds and Janne M. Sjodahl:

"Sometimes the reader will be misled by the numbers of the Bible because he does not know how they originally were used. "Ten" sometimes stands for "several." "Forty," often means "many," "Seven," or "seventy," denote a large and complete number, although uncertain to the speaker." (Commentary on the Pearl of Great Price, George Reynolds and Janne M. Sjodahl, 1965)

For whatever reason it appears that it is God Himself who assigned this value to whatever dealings He had with His children. Throughout the Bible the number forty seems to be associated with a period of preparation or trials for the person or persons involved; forty days for an individual man and forty years for a nation.
It even took forty years to build the Salt Lake Temple, but we know that really took forty actual years.
In Jewish custom the number "four" represents completeness and relates to the notion that the fortieth year was when a man was at the height of his life(Uh oh, that means I'm over the hill); and from this fact forty years came to represent a generation.