It's rather simple really. Go to Morning star cavern (just outside Mojave Outpost) and stick to the cliff, walk away from the mojave outpost and just keep walking up the cliffs. You have to walk along vertical cliffs often but if done right you can get out the map. Pretty useless and I don't yet know how far out you can go but still a find none the less!

Oh and I'm on xbox if you wanted to know.

Images:
[img]http://i138.photobucket.com/albums/q272/Tornroot/Photo-0802.jpg[/img]
A quick snap of the view I took on my travels:
[img]http://i138.photobucket.com/albums/q272/Tornroot/Photo-0804.jpg[/img]

Ok, you can go pretty far. I think you can go as far until you dissappear on the pip-boy. Then there's an infinite amount of radiated water for you to swim in!