there's at least two different functions - one for general math, one for vectors (physics stuff). basically yeah you put two values in and it eases between them
"interpolates between a and b by t. t is clamped between 0 and 1."
but for that script it'd be great to have you accelerate and decelerate when moving
you could set the time for the lerp to be like 10 seconds, then you'd pretty much have a "takeoff"
This script:
https://github.com/patflannery/unity-awesomeness/blob/f09a384c811ed07fa46c76e80b679adcf74aff05/Camera/FreeFlightCamera.js
Apply lerp:
http://docs.unity3d.com/ScriptReference/Mathf.Lerp.html