A fluid dispenser (10, 110, 210, 310, 410, 510, 610, 710) for containing and dispensing metered amounts of fluid and including a pump (20, 120, 220, 320, 620, 720), the fluid dispenser (10, 110, 210, 310, 410, 510, 610, 710) comprising: a reservoir for containing fluid; a chamber (24, 124, 424) positioned substantially within the reservoir for containing a quantity of the fluid; a piston (35, 135, 235, 435, 535) moveable within the chamber (24, 124, 424) to draw fluid into the chamber (24, 124, 424) when the piston (35, 135, 235, 435, 535) is moved in a first direction with respect to the chamber (24, 124, 424), and to discharge fluid from the chamber (24, 124, 424) when the piston (35, 135, 235, 435, 535) is moved in a second direction opposite the first direction; a user-manipulatable control (40, 140, 240, 340, 440, 540, 640, 740) coupled to the piston (35, 135, 235, 435, 535) and movable to move the piston (35, 135, 235, 435, 535) with respect to the chamber (24, 124, 424); and a pawl (277, 477, 577, 579, 877, 977) located between the piston (35, 135, 235, 435, 535) and a wall of the pump (20, 120, 220, 320, 620, 720), the pawl movable with respect to the piston (35, 135, 235, 435, 535) to selectively permit and inhibit movement of the piston (35, 135, 235, 435, 535) in at least one of the first and second directions; characterized in that the piston (35, 135, 235, 435, 535) and the chamber (24, 124, 424) collectively define at least a portion of the pump (20, 120, 220, 320, 620, 720); and in a first state of the pump, the piston (35, 135, 235, 435, 535) is limited in movement to a first stroke distance to discharge a first quantity of fluid from the chamber (24, 124, 424), and wherein in a second state of the pump, the piston (35, 135, 235, 435, 535) is limited in movement to a second stroke distance different from the first stroke distance to discharge a second quantity of fluid different from the first quantity of fluid. a reservoir for containing fluid; a chamber (24, 124, 424) positioned substantially within the reservoir for containing a quantity of the fluid; a piston (35, 135, 235, 435, 535) moveable within the chamber (24, 124, 424) to draw fluid into the chamber (24, 124, 424) when the piston (35, 135, 235, 435, 535) is moved in a first direction with respect to the chamber (24, 124, 424), and to discharge fluid from the chamber (24, 124, 424) when the piston (35, 135, 235, 435, 535) is moved in a second direction opposite the first direction; a user-manipulatable control (40, 140, 240, 340, 440, 540, 640, 740) coupled to the piston (35, 135, 235, 435, 535) and movable to move the piston (35, 135, 235, 435, 535) with respect to the chamber (24, 124, 424); and a pawl (277, 477, 577, 579, 877, 977) located between the piston (35, 135, 235, 435, 535) and a wall of the pump (20, 120, 220, 320, 620, 720), the pawl movable with respect to the piston (35, 135, 235, 435, 535) to selectively permit and inhibit movement of the piston (35, 135, 235, 435, 535) in at least one of the first and second directions; characterized in that the piston (35, 135, 235, 435, 535) and the chamber (24, 124, 424) collectively define at least a portion of the pump (20, 120, 220, 320, 620, 720); and in a first state of the pump, the piston (35, 135, 235, 435, 535) is limited in movement to a first stroke distance to discharge a first quantity of fluid from the chamber (24, 124, 424), and wherein in a second state of the pump, the piston (35, 135, 235, 435, 535) is limited in movement to a second stroke distance different from the first stroke distance to discharge a second quantity of fluid different from the first quantity of fluid.