Mark Evans talks about the mainstream-ification of GPS in his recent post. As noted, GPS technology has been around for 30+ years but it is only until the past couple of years that it's really started catching on and becoming a mainstream technology.
My first GPS experience was in the mid 90's when I was working for a GIS (Geographic Information System) software company. It has been quite interesting watching this industry grow and going from being a novelty where people would say "so what can you do with it?" to them saying "let me show you the directions on my GPS".
So what has been the catalyst for this industry. I firmly believe it is due to data availability on a couple fronts. Firstly, up until 2006 civilian GPS suffered from a built in selective availability (SA) feature. With the systems origins in the military, a random error was introduced into the system for apparently security purposes. This meant that for example anywhere in the US you'd have an error margin of about 10m in any direction.
In 2006 this was disabled (or set to 0) so finally it was possible that a $200 device can pinpoint you down the center of a street. Prior, it was difficult to explain to a user why the device was placing us in the middle of a field when we were standing in our backyard.
The second and probably as important catalyst to the growth of this industry is general data availability. Introduce MapQuest, Google Maps and numerous other available data sources, consumers can now see where they are on a map.
Map data is expensive - very expensive to collect and maintain. Thus there was a period throughout the industry where any licensing of data was extremely expensive as producers were very protective of their data. Canada was particularly bad in having a cost recovery attitude to data and the US (starting with the USGS) was a pioneer in making data available to the public.
One of my greatest frustrations when working within the Geo industry was the lack of data. I am a firm believer that providing data and making data accessible at a very reasonable cost has much greater benefit. Data on it's own is quite dull until you can wrap it into some application. Consumers and users in general relate to data through an application. But the moment you restrict access to data, building an application to access it will be hindered as well. The end result, no data and no applications for consumers.
Like I said, my first GPS experience was almost 15 years ago though my parents got excited about geo-technology and map data when they downloaded Google Earth. Since then they purchased a GPS unit for their car and tell all their friends about it.
This same concept applies to any other data intensive industries including web metrics. Right now we are in a transition stage. Most trusted web analytics are buried in corporations taking a cost recovery approach though with a number of initiatives, there is a trend to opening up and making much more data available to users.