Market research firm iSuppli is predicting that the use of GPS navigation by smartphone users will outpace the use of personal navigation devices and that by the year 2011, all smartphones will have fully functional navigation capabilities:

Previously, handsets were not seen as a threat to the dominance of the PND due to poor battery life, unclear pricing structures and small displays. However, as smart phone design moves forward, many of these issues have been or will be resolved, leading to increased market share for navigation applications on phone handsets.

Read more Navigation on Smart Phones: Who Needs a PND? (seen via cnet)