DC Universe Online maps show you where to find everything
A while back, an OCD DCUO player put together a detailed map of the game's main hub for heroes, The Watchtower. Today, another industrious fan took it three steps further by building detailed interactive maps for all of DCUO's two major cities, Gotham and Metropolis, inside of Google Maps. And now he's in the process of adding icons to help you locate everything you could possibly want to find in the urban sprawl.
Going by the name Happy-Cat (located in "The Happy Cave" according to his profile) on DCUO's official forums, this hero didn't make the original maps, but has done a tremendous job of migrating and updating them to reflect the new positions of collections, briefings, bounties, and races as the game gets patched. He's still in the process of updating them with new information, so be sure to jump into this forum discussion to let him know what you'd like to see on the maps next.
As always, you can download and play DC Universe Online for free, and I highly recommend you do--especially after the latest content patch.