Google (Nasdaq: GOOG) just changed everything… again.

This time, it seems that Google is trying to kill stand-alone GPS navigation devices – and the companies that make them.

The rumor that the firm might offer turn-by-turn GPS navigation has just turned into reality, as the tech giant has brought the feature to all its Android 2.0 devices.

For free.

And the effect this has had on shares of GPS firms is notable…

GPS Stalwarts Crushed As Google Crashes the Party

On Wednesday (October 28), both Garmin (Nasdaq: GRMN) and fellow GPS provider TomTom (AMS: TOM2) saw their plunge by 16% and 20% respectively.

It seems investors are thinking the same thing: why pay $300 for a stand-alone GPS navigator when you can get it free on your phone?

However, this only applies to folks who own Android phones and it's unclear when Google will roll out the feature to other operating systems. Still, it's promised a future launch for devices that have the hardware capable of handling the software.

With the software providing turn-by-turn spoken directions, Google's street view map and speech recognition (drivers can simply speak an address or destination to get a route) makes it a killer app.

And it's unlikely Garmin or TomTom can survive such an erosion of their market shares without some very nimble repositioning.

Let's be clear: Standalone GPS navigators will likely still have a niche, but it's fast becoming a very small niche.

As Google rolls this software out to more phones – and more people buy smartphones – the stand-alone GPS could quickly take over most of the current consumer space.

In short: If you're invested in Garmin and TomTom, get out. The stocks may bounce back a little from current lows, as investors realize this won't be an overnight transition. But make no mistake: Both companies are in big trouble, now that the mighty Google has crashed the party.

And of course, Google continues to expand its dominance of the digital world.

Good investing,

Ryan Cole