When you find the perfect apartment, but it doesn't have a closet, you have two choices: You can either A. throw away all your clothes, or B. get creative. I chose B.
Finding an apartment in New York is not easy. In fact, it is damn near impossible. So when I found one that I really loved, and could (kind of) afford, that was in a great neighborhood and steps (literally steps, not broker-speak steps, which means at least five blocks) from a subway, the fact that it didn't have a closet did not seem like that big of a deal to me. In fact, my designer-brain went into hyperdrive and immediately identified the hallway leading to the bathroom as the perfect spot to press into service as clothing storage.
Originally my plan was just to get one or two garment racks, but it quickly grew into something much more ambitious than that. I envisioned making use of the whole wall, with not just a few freestanding hanging racks but a whole system of drawers, hanging bars, and shelves. Basically, I aimed to create the walk-in closet of your dreams in an apartment that didn't have a closet at all.
I looked at a few different wall-mounted closet systems, and surprise, I chose the one from IKEA, because I already spend all my money in rent and, at the time, didn't know how long I would stay in the apartment. Also, IKEA sells laundry baskets that neatly integrate with their closet system, and I was pretty jazzed about that. So I ordered all my stuff, and had it delivered to my apartment, and then a (very very) kind friend "helped" (read: he did the whole thing while I kept a running commentary and drank scotch) me install it all.
And now? I really do have kind of a dream closet. Of course the whole thing is customized (by me) particularly for me, so I have what might seem like a very small amount of hanging space, and a very large amount of shoe storage, but it works for me. Part of the hanging space is occupied by a shelving unit I bought from Amazon, which sits on top of the IKEA shelves and holds my sweaters. I was a little concerned that its weight might cause the shelves to rip out from the wall, but I shouldn't have worried: those things are rock solid. (Thanks Christian!)
The very top shelf holds a suitcase and an assortment of boxes that contain tools and craft supplies and my 'junk drawer'. This, in addition to the clothes storage bits, is a welcome addition to an apartment that can't be bothered to have a single closet. The lesson, for anyone moving into a storage-challenged space, is: if you have a wall, you can build a closet. The only limit is your imagination (and the goodwill of your very handy friends).