Some embodiments include thyristors having first and second electrode regions, first and second base regions, and material having a bandgap of at least 1.2 eV in at least one of the regions. The first base region is between the first electrode region and the second base region, and the second base region is between the second electrode region and the first base region. The first base region interfaces with the first electrode region at a first junction, and interfaces with the second base region at a second junction. The second base region interfaces with the second electrode region at a third junction. A gate is along the first base region, and in some embodiments does not overlap either of the first and second junctions. Some embodiments include methods of programming thyristors, and some embodiments include methods of forming thyristors.