AND I'm sure Oblivions fanbase is bigger than F3s, by bigger, I mean far mor devoted. I'd do it if I could T_T
I tried doing it myself without any instructions...
1. Load up the GECK and select the default file as your data
2. Open up a cell and zoom out to the distance you want.
If you took a screenshot at this point, it would look like this
http://filesmelt.com/dl/satellite.PNG
3. Manualy remove all the crap
http://filesmelt.com/dl/satellite2.PNG
I am sure that there is some way to make the GECK hide those coloured boxes, npc spawn locations ect. Also, there is probably some way to set the zoom level better to get a more uniform map, instead of some areas being more zoomed in.