We first saw the idea of the mural on the Pottery Barn Kids website (the image is no longer available on the PB site).
We painted all the walls in the room, and let them dry for a few days before proceeding to paint the mural.
We found a map online that we wanted to use, and photocopied it onto an acetate (Eric campaigned for an upside down map - the answer was no). We did decide to use a pacific centric map so that the Philippines would be in the middle of the room.
We borrowed a projector from our friends, outlined the image from the acetate using chalk, then painted right over the chalk outline with a small craft paintbrush.
We saw this image on design dazzle, and we love the compass on the ceiling and want to incorporate it into our room too. We have the acetate, all that's left to do is paint it.
As much as we like how the mural turned out, if we were starting the room over again, there is one thing that we'd do differently. We had toyed with the idea of painting the wall with chalkboard paint, but I was too nervous that the color would be too dark (and then I'd want to paint over the expensive chalkboard paint), If we were to begin the room again, I would paint the wall with chalkboard paint, and paint the mural on the chalkboard. That way, you could draw all over the wall and erase all your drawings, but not erase the map outline.
I'll leave you with one more picture of the mural.