Item #1: I have a private glory hole directory on my site. Currently there are listings for AL, AZ, CA, FL, IL, KS, ME, NY, PA, VA/DC, and WA in the US, and Vancouver, BC and London, UK. Interested men in these areas can send me a private inquiry and I will send them the contact info. (special free offer for LPSG members, otherwise only paying members of my site have access to this info)
Advantage: no risk of getting arrested at a private GH for lewd conduct (as you would have at a bookstore or rest stop GH); many available for regular appointments; some available for walk-in service.
Disadvantage: for men only ~ most are gay-owned; some of the GH owners want to also get fucked thru their glory hole. Str8 and Bi guys are usually welcome to visit, but women are not.
Item #2: Glory holes you can make yourself: Doors with holes cut in them; temporary walls of plywood with holes cut in them; Cardboard refrigerator boxes with holes cut in them; Bed sheets hung from the ceiling with holes cut in them; Sheets of black plastic garden liner hung from the ceiling with holes cut in them; Shower curtains wilth holes cut in them suspended from tension rods spanning a hallway... I even made one from two 30"sections of 2x4 which were cut so that put together they made a sort of "cock pillory", then they were slid into a pair of brackets I attached waist-high on either side of an open door frame. A curtain could be hung to the top of the cock pillory to protect anonymity, or it could be left open so the top could grab the head of the cocksucker. A couple of guys in Phoenix cut a glory hole in their garden gate door so men could walk right up and get blown outdoors (in an area proteced from the street).
With a liittle ingenuity you can make your own set-up, temporary or permanent, in your own home.