I found this (http://www.teamfc3s.org/calc/convert_pressure.php) on a sister forum, and thought it may be useful to people on here too.
Perhaps this could be made a sticky to help people find it? ;)
This site is also really good, it has a full unit converter, including pressure, but lots more as well.
http://www.digitaldutch.com/unitconverter/
(http://smilies.jeeptalk.org/contrib/sarge/Slam_anim.gif)
And there is a great downloadable utility here:
http://joshmadison.com/software/convert/
22 different categories including power, pressure & torque
Kevin
Here\'s another one, many sorts of quantities, in many sorts of units :
http://www.onlineconversion.com/
René