Before you start writing comments about how Wal-Mart and Costco are ruining America, let me say this: I don't doubt that profit margins are slimmer than ever, making it tougher for small retailers to compete with big box stores.  And I don't doubt that consumers are scaling back discretionary purchases these days, opting for cheaper models, or waiting longer to upgrade.

But lower pricing means GPS devices are now affordable to millions more potential customers, and competition is driving innovation. Feature sets are growing, and prices are falling almost weekly. There's never been a more diverse line-up of GPS devices to choose from, and there's a GPS to fit almost any price point.

If I were a retailer, I'd probably miss the days of $3,000 custom installed GPS setups, complete with comfy profit margins and costly professional installation charges. But as a consumer, things have never looked better for GPS.  A good quality GPS device can be had for well under $250 these days (even less if you sacrifice some features), and that number is quickly moving below the $100 watermark.

I highly doubt the PND market will be significantly eroded by cell phones any time soon. It reminds me of predictions that DVDs are dead, and that digital downloads are the future. That's true, but DVD sales are still going strong, and it's going to take many years, and a lot of bandwidth infrastructure upgrades, to make that a large-scale reality.

Similarly, I believe the dedicated PND still has life left in it, and represents the best possible navigation experience today. As for the future, I do agree that the line between cell phone and PND will blur, as more capable smart phones become available. But I also believe it's going to take some significant technology improvements in battery life, GPS receiver power consumption, display quality, and usability before we see any serious erosion into the PND market.