Hello, Peter Molyneux.

Another one for the affect/effect homophones category. This one comes from a Joystiq article about Wii Sports Resort.

The original Wii Sports currently resides in like, four out of every five households on the planet -- why wouldn't the Japanese gaming populous spring to consumer action when the MotionPlus-bundled follow-up landed on store shelves?

The problem here, though, is that 'populous' is an adjective, whereas 'populace' is a noun. So, more correctly, it would be 'the Japanese gaming populace' which springs to action. This mistake makes sense especially in the realm of video games, as there is a game called "Populous." Thus, the term could come to be associated with the game and be perceived as a noun.

Source: http://www.joystiq.com/2009/06/30/wii-sports-resort-sells-over-350k-copies-in-four-days/