FREESCALE SEMICONDUCTOR - MPX10DP - IC, PRESSURE SENSOR, 0 TO 10KPA, SIP-4

Works exactly as explained in the datasheet. Problem is you'd better read the datasheet and take note of the fact that it's NOT temperature compensated. You're going to need your own compensation circuit if you need calibration to remain constant for any length of time at all (i mean in less than a minute it will drift significantly even just sitting there) and probably an instrumentation amplifier to make the tiny tiny output range of 10's of millivolts usable. But then you need some good filtering for noise too... so this little guy comes with some extra design challenges best done by the same people who offer pretty much identical sensors like the MPX5010DP which are compensated and amplified onboard already.

Needs separate voltage amplifier circuit since the output voltage change is very tiny.