Some embodiments include methods of programming a memory cell. A plurality of charge carriers may be moved within the memory cell, with an average charge across the moving charge carriers having an absolute value greater than 2. Some embodiments include methods of forming and programming an ionic-transport-based memory cell. A stack is formed to have programmable material between first and second electrodes. The programmable material has mobile ions which are moved within the programmable material to transform the programmable material from one memory state to another. An average charge across the moving mobile ions has an absolute value greater than 2. Some embodiments include memory cells with programmable material between first and second electrodes. The programmable material includes an aluminum nitride first layer, and includes a second layer containing a mobile ion species in common with the first layer.