No, guitar porn is not some new form of adult entertainment, it means the thrill of great guitar playing and gear for those who love the instrument.
I'm one of those people that loves to spend time at Guitar Center and Sam Ash, staring at what I can't afford. (I call it fantasy guitar buying, like fantasy baseball.)
It's enormous fun indulging my love of guitar and guitar playing, and it's enormous fun to indulge it, whether I'm writing about it, playing in my spare time, downloading clips on YouTube, and wishing I could sound as good as my favorite players.
Two recent guitar porn indulgences for me as a writer included covering the '59 Les Paul, which is the most valuable rare guitar in history, and the hot rod guitar companies of the eighties.
Both are on complete opposite ends of the spectrum of course. The '59 Les Paul is the holy grail for collectors, where the big guitar companies of the '80's like B.C. Rich, Jackson, and Kramer, were the machines that drove innumerable metal bands and shred players.
1959 was the year the Les Paul hit its peak of development, and as Norm Harris, owner of Norm's Rare Guitars, will attest, "They hit it right on the nose. It's the entire chemistry of the guitar, sound, feel, sexiness, the color, how it looks onstage." (Renowned studio musician and guitarist for Toto, Steve Lukather, owns a '59, which you can see him playing in old Toto videos and concert footage of the band, and his '59 is currently valued at $3-500,000.)
In the eighties, the hot rod companies like Jackson and Kramer actually came close to putting Fender and Gibson out of business until Slash brought the Les Paul back. Before the hot rod companies, you had to pay a guitar repairman to customize your guitar, and with these companies it was the closest you could buy a customized guitar off the rack.
Eddie Van Halen helped launch a lot of modern guitar design when he put his own "Frankenstein" guitar together from spare parts. Fender even built exact replicas of his famed red and white striped guitars you could buy for $30,000, which is absurd considering his original "Frankenstein" strat probably cost him $300 or less to put together himself. (If Ed ever decides to sell his original, it's estimated at a million.)
If you can't afford an original '59 Les Paul (And who among us can?), supposedly the '59 reissues that Gibson recreates with modern technology are pretty close to the real thing. With today's technology, you can also age the guitar's wood (like a fine wine, wood sounds better with age), and recreate a guitar down to the micrometer so it feels like a comfortable instrument you've been playing for years.
Again, guitar porn is what turns players on, whether it's great guitar playing, top notch gear, the feel of the instrument, the excitement of learning and growing to new levels. But if you're among the guitarded, it all goes without saying.