Usually a shaky video of a phone in use is not a big deal — that all changes when that phone is Apple's iPhone 4S, five days before its launch.

The sound-free video, above, leaked on the Chinese forum AppVV.com, appears to show a 4S being put through its paces. The BrowserMark number is significant as it's roughly double the number you'll get on an iPhone 4 running iOS 5 — meaning the iPhone 4S will browse the web at twice the speed of its predecessor.

There are other iPhone 4S videos out there, but all appear to be demonstrated by an Apple employee. This is the first video that is decidedly not Apple-moderated.

The site does not explain how the phone was obtained ahead of launch. So how do we know it really is an iPhone 4S? Because Siri appears to be baked right into the OS — note the preferences screen that allows you to select English (in Australian, British or American dialects), French or German. Also note the options to have Siri talk back and to activate the service when you lift the phone to your ear.

Want to learn more about Siri? We have its history, and an interview with the app's co-creator, here.

[Via Macrumors]

BONUS: 10 Absurd Questions for Siri