Methods and apparatus are disclosed for generating fluid pulses in a fluid column, such as within a well. A described example fluid pulse generator has a valve member comprising a piston that is linearly movable within a piston chamber to control flow by selectively obstructing a fluid passage. The fluid passage may extend around at least a portion of the piston chamber and intersect at an angle relative to the axis of movement of the valve member. The piston is linearly movable, such as from a closed or minimal-flow position to a maximal-flow position, and optionally to any of a number or range of positions therebetween. The position of the valve member may be varied to generate fluid pulses of a selected pattern of duration, amplitude, and so forth, to generate a signal within the fluid column detectable at a location remote from the fluid pulse generator.