Google's acquisitions so far

After hearing about Google's acquisition of Postini a few days ago, I thought I should do a post on summarizing Google's acquisitions over the years. However, after some googling, I stumbled upon this excellent post. A great roster for anyone looking to study Google's acquisitions. Some interesting analysis of the post:

• Google has made over 38 acquisitions since 2001, of which 12 were made in 2007.
• Google's largest acquisition so far in terms of cost has been Doubeclick (US $3.1B)