Again, for room temp, my experience suggests that using the
Steinhart–Hart equation - Wikipedia
Tracks to within 0.5F at room temp based on 4 separate didital thermometers. Not bad.
Interesting; but that's when you know the coefficients in the equation and therefore the equation. The problem is when those coefficients are not known for the particular thermistor one is trying to use, in which case they have to be found and that's a complicated and time consuming process which requires special instrumentation to be used as standards.
I used a thermistor a while ago and I could get temp readings within 0.1C; but that was based on the manufacturer's provided coefficients and equation.
http://forum.arduino.cc/index.php?topic=194174.msg1434134#msg1434134