moar phun @ http://xkcd.com

The primary purpose of the DATA statement is to give names to
constants; instead of referring to pi as 3.141592653589793 at every
appearance, the variable PI can be given that value with a DATA
statement and used instead of the longer form of the constant. This
also simplifies modifying the program, should the value of pi change.
-- FORTRAN manual for Xerox Computers