If you could use some storage under the bed, you can hack two IKEA Expedit 5×1 shelving units into a platform storage bed along with two sheets of MDF, a 4×4-inch post and a few floor protectors.
Furniture modification weblog IKEA Hackers shares this method for assembling the bed: one expedit unit is used horizontally, while the other is cut down to form storage for the end of the bed. MDF is added on top of the two units, and the 4×4 post is used in the corner without any storage to prop up that end of the MDF.
While this design can be handy if your bed will always be in a corner, I think it could be improved by simply using a 5×1 Expedit on each side with the MDF on top. You can always add the 4×4 posts in the middle if needed for stabilisation, and you can cut in another Expedit section for the foot of the bed.
Expedit Bed Frame [IKEA Hackers]