I love the concept, but I'm extremely skeptical that the dithered PNG images are smaller than a (much nicer looking, but lossy) JPEG. It's fine if that's the aesthetic they're going for, but it doesn't seem like it would reduce the server load...<p>For the record, one of the 640x480 PNGs is 41 KB, and I just saved an elaborate, full-color (and higher resolution) JPEG at a smaller file size (quality was around 50, I think). The JPEG looks completely fine on my (normal DPI) screen.<p>Edit: It <i>does</i> look like they scale up the PNGs (at least when I view their site), and lossless images definitely scale better. Maybe that was the motivation.