Google Maps has hit a new milestone as the first Android application to surpass the 50 million download mark. The free application has seen many revisions since its public introduction in 2008 — as part of Android 1.6 — and now includes 3D modeling with multi-touch zoom and panning, free voice-guided turn-by-turn navigation, and support for Google’s Latitude and Places products. Given that it’s available on every iteration of Android — that we can think of — we’re not surprised to le...