As you know, Google's freebie turn-by-turn navigation app for Android 2.0 surfaced this week. After driving around our patented testing track for a few days, I can tell you what's great—and what's surprisingly bad—about it.

Today, as soon as Google showed off its beta GPS navigator, the stocks of Garmin, TomTom and other companies in that industry fell into the toilet. It's hard to compete with free Google apps, but that's not why they're screwed...