In the 2004 film The Aviator, a biography of Howard Hughes, it depicts the reclusive billionaire storing his own urine in mason jars in a screening room. Is this true? Note that the linked Wikipedia article also makes an (unsourced) statement about this.
There is an overwhelming consensus of 'Yes he did.'
According to Howard Hughes: The Secret Life by Charles Higham (1993):
Page 121 describes the great lengths he had people go to accomodate
He had a team of engineers work around the clock to design a more comfortable bed for him in moving sections with an aperture and a pipe to conduct out urine and feces.
Page 191 describes his fear of touching dirty objects.
He didn't risk turning the doorknob, even with gloves. He would kick the door as a signal and the drivers would open it. He was obsessed with the toilet. He urinated on the floor; then he covered it with Kleenexes to sop up the fluid. He refused to let his men use the toilet; instead they had to use empty ice buckets.
By page 247, and further descent into mental illness, describes the Mason jars.
His fondness for Empirin and mainlining codeine had affected his kidneys; and his fear of anyone's seeing his urine still compelled him to bottle it in Mason jars.
Contrary statements do exist.
According to Jim Whetton, when asked by the Standard Examiner about Hughes' urine collection, he responded with:
“He never did such a thing,” Whetton said. “The man was a recluse, period. That’s it.”
There are way more books, and media publications, that describe Howard Hughes' treatment of his urine. One Google Search can confirm that. According to page 426 of "Howard Hughes: His Life and Madness" by Donald Barlett - Hughes did (Credit: Bluecollar). Jim Whetton, although a great friend and colleague, seems to be alone in his defense of the urine behavior. Could Jim be simply trying to maintain a positive legacy for a lost friend? Possibly yes. Could many authors of various publications simply be exaggerating the urine incidents as a part of an extravagant scheme to show that Howard Hughes - the rich and powerful - had a flaw? Possibly yes.