Early start, and education starts at home: Developing an interest in science starts at the age of a child. Find a science topic your kid(s) like and help develop and foster that interest. While most children who show an early interest in science don't become scientists, instilling a sense of curiosity, rationality and imagination will help sustain an interest in science.
Schools need to teach it better: Not much to say here, but how well science is taught depends on where you live.
That's really all there is to it. I think athletes and celebrities will always be more admired than scientists, but a more educated populace will make science at least more appealing to the average person.