I find maps quite fascinatng, they are documents of our limitations, the boundaries and borders of our perceptions as well as the charting of our knowledge. Maps aren't always necessarily geographic and in recent years as we have shifted our horizons toward the digital, cartographers have emerged with charts and maps of the new geography. Works by Martin Vargic, executed by hand in his spare time using Photoshop were some of the earliest attempts, and now comes a new piece by him and another artist, Jay Simon. Together they have created a map with an old world feel to it, but it is anything but old, hundreds of net ventures are charted and mapped, fascinating. You can buy a copy here.
You can also check this link out for another, and ongoing, approach to mapping digital space.