Google is moving into your market.

For tech companies, few words are more frightening, and yesterday we saw why. The mere announcement of Google Maps Navigation sent shares of established GPS device makers like Garmin (GRMN) and TomTom into an ugly downward spiral.

Shares of Garmin lost 16 percent of their value and shares of TomTom plummeted more than 20 percent to a new 52-week low. This, despite the fact that Google’s (GOOG) new turn-by-turn mapping service is currently only available for Android 2.0 smart phones like the Droid from Motorola (MOT).

Clearly, investors already see where this is headed. Who will pay for a Garmin or TomTom unit when they’ve got an Internet-connected smart phone that offers turn-by-turn voice guidance for free? It might be a bit slow coming out of the gate given the current paucity of Android-based smart phones, but once more handsets arrive at market, Google Maps Navigation will undoubtedly have a significant impact on sales of dedicated GPS units.

And if Google brings the service to Apple’s (AAPL) iPhone, as the company hopes to, it’s going to be even worse.

“With this product, Google injects itself into a new market and has the potential to cause serious pain for the existing players, like Garmin and TomTom, while giving potential customers one more solid reason to switch to a Google-powered phone,” said Gabriel Consulting Group analyst Dan Olds. “It’s a lot easier to justify the switch to a new device if it takes the place of two devices, like a phone and a navigation device, and if it does the job better.”

The deal and its terms were never announced and Apple has not confirmed it. But Computerworld notes a summer tweet from a Placebase customer claiming the acquisition had been made in “hush-hush” fashion. The tweet also notes that Placebase founder and CEO Jaron Waldman’s LinkedIn profile now shows him as part of the “Geo Team” at Apple. And Placebase.com, which once touted the company’s Pushpin mapping platform has been taken offline.

Reached for comment, Apple (AAPL) declined to offer one–or to confirm that the acquisition has even taken place. But assuming there has been an acquisition–I know the evidence we’re dealing with here is circumstantial at best–this might explain the increasingly strained relationship between Apple and Google (GOOG), the Apple board’s Schmidt-ectomy and the Google Voice for iPhone debacle in which the companies offered two very different stories to explain the application’s rejection/delay from the App Store. If Apple has acquired Placebase, it could certainly use that company’s technology to replace Google Maps with an in-house mapping solution.

Of course, Apple might have something else in mind entirely–adding a new layer of customization to its current map offering, perhaps. After all, that was Placebase’s forte–enhancing maps with private and public data sets (demographics, crime data, etc.). In any event, we’ll never know unless Apple tells us, and right now, the company clearly has no intention of doing so.

Yesterday the company announced Knol (defined as a “unit of knowledge”) , its improvement on the social encyclopedia. With it, the company hopes to encourage experts on a particular subject to write authoritative articles about them, which it can then rank. “The key idea behind the Knol project is to highlight authors,” Google VP of Engineering Udi Manber wrote on the company’s blog. “Books have authors’ names right on the cover, news articles have bylines, scientific articles always have authors–but somehow the Web evolved without a strong standard to keep authors’ names highlighted. A Knol on a particular topic is meant to be the first thing someone who searches for this topic for the first time will want to read.”

Oh, and one other thing: “At the discretion of the author, a Knol may include ads. If an author chooses to include ads, Google will provide the author with substantial revenue share from the proceeds of those ads.”

Ah.

Interesting idea, developing an alternative to Wikipedia that rewards contributors for their work with not just a byline, but financial compensation as well. And an easy way to redirect all the traffic Google sends to Wikipedia back to Google itself.

Which is what Microsoft did today when it purchased Multimap for a reported $50 million. “The addition of Multimap enhances Microsoft’s position as a leading provider of mapping and location platform services,” Sharon Baylay, general manager of Microsoft’s Online Services Group, said in a statement. “This acquisition will play a significant role in the future growth of our search business and presents a huge opportunity to expand our platform business beyond the U.K. and globally.”

Leading provider of mapping and location platform services? That’s a bit of a stretch. According to Nielsen Online, Microsoft’s Windows Live Maps service had 7.1 million unique users worldwide during October. By comparison, Google Maps had 71.5 million unique users, its Earth service 22.7 million. Clearly, Microsoft is in a losing battle against Google in the mapping space, though this acquisition will give it a powerful weapon with which to fight.

Then, $8.1 billion (54 times current earnings!) seems reasonable. As it did to Nokia, which today agreed to acquire mapping-data provider Navteq for exactly that sum. “This is Nokia’s largest acquisition ever,” said Mats Nystrom, an analyst at SEB Enskilda Bank in Stockholm. “This is a very high valuation for the U.S. company, so yes, this is a high price to pay. But navigation is a hot area and fits well with Nokia’s strategy.”

Indeed. With sales of navigation-ready cellphones on the rise, the Navteq acquisition would seem to leave Nokia poised to take good advantage of the booming location-based services market. In more ways than one. By acquiring Navteq, not only did Nokia “get a resource to power whatever GPS wonderfulness it plans for its own phones or future devices, it also kept a valuable property out of the hands of some powerful players with mapping interests, like Google, Microsoft and Yahoo,” notes Good Morning Silicon Valley. “All three, in fact, use Navteq data in their own mapping services. Nokia is likely to look for ways to nurture and leverage these relationships, because competition remains in the form of Tele Atlas, now in the process of being bought for $2.8 billion by Dutch GPS gear-maker TomTom.”