Geoff Chang, Apeman and others have traded suppositions in an interesting couple of HBO forum threads postulating the position of the buried artifact in the Halo 3 trailer.

Chang went so far as to take a series of images from Google Earth and, using information in the trailer and revealed elsewhere by Bungie, overlaid an image of the artifact to scale where he thinks it might be. Debate is still going on over exactly where the city of New Mombassa, the artifact, Mount Kilimanjaro and the city of Voi, mentioned in a soundtrack title, are in relation to one another to make sense of the trailer.

Thanks Ding who pointed out the threads on the front page of HBO.