Layers and Layers

I wish there were a super fast viewer for Photoshop files. A nice portion of the world map for Grapple Buggy is shaping up and it'd be great to be able to make layers for it and have them quickly viewable. Honestly I don't know of a program like this, but I wish there were the ability to open a PSD file in a fast viewer (like IrfanView or Windows Picture Viewer), then page through the layers themselves, in a simple fashion like pressing the arrow keys up/down or something.
Sure programs like IrfanView can open a PSD and display it 'flattened', but the trick would be flipping through the layers. It'd be really nice to have monsters on layer, level actions on another, written notes on another layer, and the environmental surroundings on another layer, for example.

Photoshop is great to use and create the images, but for simply viewing it's expensive, slow loading, and not everyone has the program. Most PC users have those simple file viewing programs. Maybe that's the problem, those are too simple and I'm looking to do something complicated. Regardless it be great to use such a program with the rest of the Grapple Buggy team, sharing the world map with them and flipping through layers to see how the levels fit together.

In the meantime, do know that things are chugging along at a good clip, with plenty of game assets swirling about, being carefully put into place by knowing hands.