http://www.straightdope.com/classics/a3_395.html
My apologies if this has been covered umpteen times. The archive searches are entirely unproductive and what I have to say is brief.
Re: Running keeps you drier
Unless you have a hat on.
See:Which will keep you drier, running through the rain or walking?
16-Oct-1992
http://www.straightdope.com/classics/a3_395.h
tml
Oops. You were right after all. Sorry. :o
What in the world is the purpose of the original post? It adds nothing of value to the information covered by Uncle Cecil in his column. Is it stating an opinion (irrelevant)? Is it attempting to assert a fact (what evidence)? Is it just there to have said something?
Dystopos, trust me, brevity here isn’t the goal. 
DSYoungEsq -
If you read the original column, you realize that Cecil says there are only two parts to the problem, 1)your head and 2)the front of you.
If you wear a hat, you are still faced with the question of getting your front wet.
Cecil said this part of the equation is constant, so the answer becomes:
cases:
a) no hat: run
b) hat : walk or run, no difference
c) umbrella: be a sport, share with the guy with one of the other guys
I failed to digest the original column with the appropriate solemnity. It addressed a very specific question with a few haphazard experiments that ignored a lot of variables such as type of rain, odds of slipping, walking and running speeds, parts of the body that it is more of a nuisance to get wet, etc. Among the variables that was addressed, however, was rain protection. I regret to have ignored that qualification in the original article.
My point in commenting was to encourage Dystopos, a new poster, to expand upon whatever idea he had in making the comment in the original post. From the brief commentary we (or at least, I) couldn’t decipher exactly what point was being made. Some new posters here think that there is a preference for brevity; my post attempted to show that clarity is more valuable.
Alas, Cecil also failed to discuss whether the results would be different in the Southern Hemisphere, where people run clockwise in the rain, as opposed to the Northern Hemisphere, where people run anticlockwise.
(Throwing an appropriately sized monkey-wrench at Dex…)