Sharp is arguably one of the leaders of infrared distance measurement modules and these modules are very popular within the robotics community. These modules have a detection distance of 10 to 80 cm with an analog output voltage that can be directly fed into a microcontroller ADC. The exact part number for this module is GP2Y0A21YK.
These units have a JST connector and come with the matching pigtail connector wires.
Datasheet