Noted. 
This is what I get from Wikipedia for the definition of
"Theory":
The word theory has a number of
distinct meanings in different fields of knowledge, depending on
their methodologies and the context of discussion.
In common usage, people often use the word theory to signify a
conjecture, an opinion, or a speculation. In this usage, a theory
is not necessarily based on facts; in other words, it is not
required to be consistent with true descriptions of reality. True
descriptions of reality are more reflectively understood as
statements which would be true independently of what people think
about them. In this usage, the word is synonymous with hypothesis.
This common usage of theory leads to the common but misguided
statement "It's not a fact, it's only a theory."
In science, a theory is a mathematical or logical explanation, or a
testable model of the manner of interaction of a set of natural
phenomena, capable of predicting future occurrences or observations
of the same kind, and capable of being tested through experiment or
otherwise falsified through empirical observation. It follows from
this that for scientists "theory" and "fact" do not necessarily
stand in opposition. For example, it is a fact that an apple
dropped on earth has been observed to fall towards the center of
the planet, and the theories commonly used to describe and explain
this behaviour are Newton's theory of universal gravitation (see
also gravitation), and general relativity.
So, I guess, it is very easy for a layperson like me to be confused
with the term in science. But still, on the note of Evolution, I
have been prowling the net on the contentions between the
creationists and evlutionists, and found that there are a lot of
arguments from both sides. Interesting to note that In the US,
according to a survey published in Nature in 1997, four out of 10
scientists believe in God. Just over 45% said they did not believe,
and 14.5% described themselves as doubters or agnostics.
Here is one interesting read for non-scientist:
http://www.newgeology.us/presentation32.html
