WASHINGTON, USA: When Google notified manufacturers of GPS navigation units, early this week, that their services would no longer be needed. It didn't say so explicitly -- the news came in a corporate blog post about an improved Google Maps smartphone program offering turn-by-turn directions -- but the company didn't have to.

The imminent arrival of a no-charge navigation service on phones running Google's latest Android software, complete with real-time traffic data and satellite and street-level views of a route, made stand-alone GPS devices look suddenly redundant.

GPS manufacturers' share prices promptly fell off a cliff; Garmin's dropped about 16 percent and TomTom's plunged by 21 percent Wednesday.

Wednesday was a not-atypical day for the Mountain View, Calif., Internet giant. Perhaps more so than any other company since Microsoft at its peak, Google can spook competitors and enthrall users just by introducing a product.

You could see the same dynamic in late September, when Google introduced a Web-based fusion of e-mail, instant messaging and collaborative editing called Google Wave-- and hype-intoxicated Web users who weren't necessarily sure what Wave did began groveling for invitations to try it out.