Ladders come in a variety of sizes. What they don't come in is a storage case. And most ladders, those bought at hardware shops, at least, don't make for great living room centrepieces. If you don't have a garage, large cupboard or outdoor shed to stash a ladder, you may need to come up with some creative ideas for storing it.
In the bedroom
Try stashing the ladder under your bed. If you already have your off season wardrobe there, it's likely you can more easily stuff a bunch of sweaters in the corner of a wardrobe. The ladder, however, can't be folded up so easily.
In a cupboard
You've already established that you can't stand the ladder up against a wall in your cupboard. Have you tried lying it down on the floor? And if it does in fact fit horizontally, just tip it on its side and push it up against the wall. If you find yourself changing light bulbs or cleaning gutters more than a few times a month, make an effort to keep items from blocking the ladder.
Do you have a piece of furniture longer than the ladder? Stash the ladder behind a sofa, media centre, long dresser, or even behind your bed. If you have a full or queen-size bed with a bedside table on each side, it's probably long enough to camouflage the ladder.
Most newer homes and flats have laundry rooms or cupboards. You already determined that short of hanging the ladder on the ceiling, there's simply no room. Well, why can't you hang the ladder on the ceiling? Buy hooks at the hardware shop. Screw them into the beams in your ceiling -- beams are generally between 40, 45 and 60 cm (16, 18 and 24 inches) apart. Of course, if you have high ceilings in your laundry cupboard, you'll never get the ladder up there in the first place.
There's no reason you can't keep your ladder outside. You don't want to anger your neighbours with an unsightly ladder leaning against a wall, though. So lay it on its side and cover with a neutral-coloured, water-resistant cover. One that fits over a large picnic table should work. This will keep a wooden ladder from warping and a metal ladder from rusting.