Weintraub first discovered evidence in a July tweet by Fred Falonde, the founder of openspaces.org, that Apple purchased PlaceBase, a business that produces a mapping API called Pushpin and offers a mapping service very similar to Google's.
After letting the story lie dormant for the last few months, Weintraub did some investigating of PlaceBase's founder and CEO, Jaron Waldman. According to Weintraub, Waldman's LinkedIn page lists his stint at PlaceBase as past experience, with his current occupation being a member of Apple's GEO team. What that actually means remains to be discovered, and Waldman's LinkedIn page is no longer viewable publicly.
Could this explain why Apple forced Google's mobile Latitude application for the iPhone to be a web-based application and not a native iPhone application? At the time, Google explained that, "Apple requested we release Latitude as a web application in order to avoid confusion with Maps on the iPhone, which uses Google to serve maps tiles." This raised questions in the tech community over Apple's rationale, given it has already approved many iterations of to-do list applications and streaming music apps.
If Apple's plan is to compete in the mapping arena with Google, that could certainly explain Apple's reception to Latitude from Google. Is this a conspiracy theory, or some good investigative journalism by Weintraub? Let's hope Apple releases an answer in the near future.