OK.....my own feeling is that you and Mike are being penny wise and pound foolish.  Oil changes are cheap, and the oil is responsible for more than lubrication.  It keeps the engine clean, too, and with turbocharged cars has added duty in providing cooling.  Like irrationalist pointed out, a lot of it has to do with how you drive.  Extreme temperatures, short trips, and dusty conditions all reduce oil life.

Since I switched to full synthetics ten years ago, I only change twice a year.  It used to be four.   The $200 a year I spend on oil changes is, to me, a very cheap price to pay for peace of mind.