David Letterman - Maintaining Levity  David Letterman, who --
like many comedians -- often found the task of producing a
constant stream of humor rather exhausting, occasionally sought
enlightenment in unlikely places. Asked by a clerk in a pastry
shop what he wanted in his coffee one day, Letterman indicated a
balloon-filling machine behind the counter and replied:
"Helium!"  ["There's a new law in West Hollywood," Jay Leno
reported in January 2000. "When you buy a cup of coffee, they
have to give you a condom. What are they stirring the coffee
with? And watch the creamer!"]  ["Scientists at the University
of Chicago decided to test the theory that coffee is a sleep
preventative. The subjects of the experiment were given coffee
one night, and then the next night, at the same hour, they were
given milk. All went to sleep faster the second night. They were
positive that the coffee the first night had kept them awake.
They weren't told that the milk had been spiked with three times
as much caffeine as was in th