Here is the image:
The best way I can describe it is converting the image to a black/white scale (heavy white) and making all instances of black==blue.That was how I approached it when trying to recreate the effect, but had little success. I prefer a solution that is doable in GIMP, since I don't have access to any other power image editing software.
EDIT: Thanks a ton to everyone for the help. There wasn't a single asnwer here that got me exactly where I wanted to be, but they all did help. And since I know what its like to come across threads like this one, I thought I'd show my progress and what I did differently.
First, Here is the raw image I was working with for demonstration purposes.
Then, trying what one answer suggested, I created a second layer of the blue-ish color like in my example, and did a [Right Click Image] Colors-> Map-> Gradient map, but it wasn't exactly what I was looking for:
This lead me to trying the other options in that same submenu, and I came across the Palette Map option. I selected a palette of exactly 2 colors 25408f & f7f7f7 (blue and white), which got much closer to the desired output:
This is VERY close to what I was hoping to get, but I'm still not 100% satisfied. I have been playing with the Posterize/contrast tools and expect I'll find a balance that I like eventually. Again, thanks to everyone that posted.