The Billion Prices Project: the MIT's real-time global inflation indices.

The Billion Prices Project is an academic initiative that collects prices from hundreds of online retailers around the world on a daily basis to conduct economic research. We currently monitor daily price fluctuations of ~5 million items sold by ~300 online retailers in more than 70 countries.

Key Facts:

• Statistics updated every day
• 5 million individual items
• 70 countries
• Started in October of 2007
• Supermarkets, electronics, apparel, furniture, real estate, and more

The dataset is quite recent and starts between 2007 and 2008 so it's not of great use to track what happened in the past. That said, it will be very useful to track the price inflation/deflation of the next few months and years. The methodology used is described here.

Long live the BPP!