It's becoming harder and harder to find a performance enhancer drug that former Yankee pitcher Roger Clemens hasn't (sigh, allegedly) ingested, mainlined, or injected into his ass at one time or another over the course of his career: The Daily News reports today that Clemens, a one-time Hall of Fame lock who is now under investigation for maybe lying to the federal government about having taken steroids, also used to keep Viagra in a GNC bottle inside his locker.