I'm probably going to get into trouble saying this (because my comment is over-generalized) but here goes:
The way I introduce the absolute value function is to define it as the distance from the point x = a to the origin. Note that when you get to the modulus of a complex number this same exact definition will hold. (This idea is my own, but is spurred on by the fact that the absolute value and the complex modulus operators are given using the same symbol. At least in the texts I've seen. So presumably someone else out there might have had similar ideas.)
-Dan