The immediate source for this post is Snopes, but I've snooped around some other sources. As a result, I'm reasonably sure that this story is true.
Alexander Courage wrote the orchestral theme to Star Trek (above video). Under the provisions of his contract, he was owed royalties every time that theme was run or re-run.
Gene Roddenberry, creator of the show, exercised an option to write the lyrics for that song, even though he had no intention of recording or performing them. This action cut Courage's payment in half -- which was Roddenberry's intention.
So, without further ado, here are the lyrics:
The rim of the star-light
Is wand'ring in star-flight
He'll find in star-clustered reaches
Strange love a star woman teaches.
His journey ends never
His star trek
Will go on forever.
But tell him
While he wanders his starry sea
Remember, remember me
Link via blastr
Previously on Neatorama:
Star Trek: TNG Opening Theme Now Has Lyrics