Parallax's PWR-I/O-DB is a daughterboard that plugs into the BASIC Stamp 2pe Motherboard. It provides both power and a handy interface to potentiometers and servos, along with Parallax's various three-pin devices, including:

PING))) Ultrasonic Rangefinder
2x16 Serial LCD
4x20 Serial LCD
Standard Servo
Standard Continuous Rotation Servo
Mini Servo
LM34 Temperature Probe
DS2760 Thermocouple Kit
QTI Line Sensor
Passive Infrared (Motion) Sensor
The addition of an onboard voltage regulator and filtering ensures that servo noise and other intermittent loads will not disturb operation of the motherboard.

Features:

Motherboard connector: compatible with the MoBoStamp-pe and all future Parallax motherboards
Multiple power sources: +5V and Vin can be provided from either the motherboard or the onboard power jack and regulator (jumper-selectable)
Wall transformer (or battery) input: 2.1mm coaxial power jack, 6-9VDC (compatible with Parallax #750-00009)
Onboard power filtering: 1000uF filter cap for maximum suppression of noise and load transients
Interface headers: six three-pin headers (ground, +5V, signal) to interface with external devices
Other Daughterboards:

TSL1401 Linescan Imaging
TCS3200 Color Sensor
Proto-DB Prototyping Daughterboard
7-Segment Daughterboard (Master Unit)
7-Segment Daughterboard (Slave Unit)
Key Specifications:

Power requirements: 4 to 5 VDC from motherboard or 6 to 9 VDC from external supply
Communication: N/A
Dimensions: 1.35 x 1.35 x 0.68 in (34.29 x 34.29 x 17.39 mm)
Operating temp range: -32 to +158 °F (-0 to +70 °C)

ROHS Compliant, Made in the USA

Downloads & Resources:
BASIC Stamp MOBO Family Overview
Power I/O Daughterboard Documentation (.pdf)