Some embodiments include methods of forming memory structures. An electrically insulative line is formed over a base. Electrode material is deposited over the line and patterned to form a pair of bottom electrodes along the sidewalls of the line. Programmable material is formed over the bottom electrodes, and a top electrode is formed over the programmable material. The bottom electrodes may each contain at least one segment which extends at angle of from greater than 0° to less than or equal to about 90° relative to a planar topography of the base. Some embodiments include memory structures having a bottom electrode extending upwardly from a conductive contact to a programmable material, with the bottom electrode having a thickness of less than or equal to about 10 nanometers. Some embodiments include memory arrays and methods of forming memory arrays.