This list is interesting, but it really doesn't surprise me that so many of the Google features we know and love were acquired.<p>Acquisition for a company like Google is smart business. While we don't know the specific dollar amount that Google paid for most of these companies, it was almost certainly less than the cost of than paying Google developers to develop these features from scratch, especially when you factor in the opportunity cost of revenue and traffic lost during the time it takes to develop the product.
Ah, Wikipedia... Google failed to acquire Begun (Russian context ad company), because Russian antitrust agency stopped the deal. (Edited the Wikipedia article accordingly).
Must admit that #1 grabs my eye straight away - I still miss DejaNews (but I still have to respect Google for keeping this information alive and accessible).