Citizen Tool by Thomas Pluck.

As Greg Samson awoke one morning from uneasy dreams he found himself transformed in his bed into a gigantic penis. A throbbing big one, he was proud to say. Uncut with a prominent vein, attached to a hefty pair of testicles and nothing else.

Heaving his balls to the carpet, Greg hunched and looked at himself in the mirror with his one big eye. "My old one was definitely bigger," he said.

He found he could locomote quite naturally as if on two ovoid wheels, and inchworm up and down more precarious footing such as steps. When flaccid, squeezing through doorways was no issue, and if he rubbed his nose on the carpet, in no time he was rigid enough to knock on a door or bat it open.

Greg showered, and nearly disappeared inside himself when the water went cold. Donning a turtleneck, scarf and hat, he headed for the train. Commuters on the sidewalk gave him wide berth.  He nodded at the men and saluted the ladies. Had to stop when a dogwalker's dozen charges all wanted a lengthy sniff. Their cold noses tickled.

The morning meeting went quite well. Greg pointed out that while they were experiencing a slight downturn as expected in the economy, their savings in payroll would meet the projections promised to investors.  The men squirmed in their chairs, eyebrows knitted in dismay, and the few women at the executive level simply stared in disbelief. The members of the board nodded in approval.

As he left the meeting, the CEO put his arm around Greg's foreskin, patted him on the shaft. "That was a fine showing, Greg is it? I see a great future for you here."