Abstract: Disclosed herein is a portable, adjustable, and foldable desk for using laptop computers or reading books in bed. The apparatus comprises a flat upper panel attached to leg assemblies at first lockable joints, and joint locks. The flat upper panel is freely rotatable about the first lockable joints on unlocking the first lockable joints for adjusting angle of the flat upper panel. Each of the leg assemblies comprises leg segments interconnected at second lockable joints. The leg segments are freely rotatable about the second lockable joints on unlocking the second lockable joints for adjusting height of the leg assemblies. The joint locks lock the first lockable joints and the second lockable joints. Each joint lock comprises a first friction plate, a second friction plate, a washer, and a locking button. The locking button locks the first friction plate, the second friction plate, and the washer using a pushing force.