Google Earth
I have been playing with the Google Earth application for the last few days, and I am absolutely blown away. This may be old news to some, but this app is just absolutely fantastic. Consider that you can literally search anywhere in the world, AND zoom in to unbeleivable levels of detail, all for FREE ! 20 years ago, this would have been something we could only dream about (from an average consumer perspective)
This is one of those apps that just reeks of a killer application. Why? Well apart from the reasons I have mentioned already, its an app that my 14 year old son AND my relatively computer illiterate wife love to use. You can just get lost looking around the entire world, all from the luxury of your computer.
The implementation is good, the interface pretty good, the provided level of detail for most areas is good. I am assuming you probably get more with the version you pay for.
At any rate, its just great. Google have been innovators for some time now, but this one is a real standout from my perspective.
I am heading back to look at the Grand Canyon, then Big Ben, and then later might head off to Niagra falls...