(Above via: Apartment Therapy.) A file cabinet is rarely found in a bedroom, but these can make great bedside tables. Paint it a bright color (like the red above) or leave it in its original condition... either way you'll be adding some industrial flair to your space. Stow away your books, magazines, school supplies, etc. If you have a drawer that locks, you can tuck away valuables and important documents for safe keeping.
(Above via: Apartment Therapy.) An old ladder can be an ideal alternative because it takes up hardly any floor space and goes vertical with organization. Attach a clip-on light for illumination. Hang books and magazines over the rungs. Fold blankets over the lower rungs to have them in easy reach. And flat rungs can be used for a water glass, vase of flowers, or alarm clock.
(Above via: Apartment Therapy.) I love chairs as bedside tables. It such a practical alternative. Books, alarm clocks, and other necessities can be placed within easy reach. Or if you frequently need a place to sit down when you put on/take off your shoes, there's always a chair.
(Above via: Apartment Therapy.) This is definitely my favorite solution. By placing your desk next to the bed, it doubles as a workspace and nightstand. It minimizes the amount of furniture in a room and looks very attractive.
(Above via: Apartment Therapy.) If your a sucker for antiques, this alternative might be for you. I see little school desks like this all the time in antique stores. The wrought-iron detail is gorgeous and the wood always has so much character. By placing one of these school desks sideways next to your bed, the taller side acts as a bedside table and the chair part can either be secondary storage, a place to store blankets, or a place to sit down.
(Above via: Apartment Therapy.) Using a wheeled cart as a nightstand has many advantages. For one, these carts are achingly cute. They come in so many styles depending on their era. (Stop by your local antique store and you'll probably find one.) You can paint them or leave them original. Things can be stored on the lower level and nightstand paraphernalia have a place up top. Plus: because of the wheels, moving these around is ridiculously easy.
(Above via: here.) Vintage suitcases stacked on top of each other also work great as an alternative to traditional nightstands. You can either opt for matching valises for a uniform look, or stack mix-and-matched ones for more color. Either way, you'll have rad vintage vibes in your space. (And you can tuck away out-of-season clothes or shoes inside of them!)