National Geographic’s Map of the Day site provides (in a vein similar to that of NASA’s Astronomy Picture of the Day, which it is strongly reminiscent of) a map along with a brief description every weekday (more or less). Maps may be from National Geographic’s stock or an old map of some sort. Catholicgauze, Contours.

In a similar vein, Matt Harris’s Show Off Your Maps! is a blog that relies on reader submissions of images of their old maps. Via MapHist.