Zynga chief executive Mark Pincus is bullish about the future of social applications, and he’s not afraid to say it. Given his social gaming company’s user and revenue growth on Facebook and MySpace, it was not surprising to hear him say so yesterday during a presentation he gave at the Web 2.0 Summit in San Francisco.

The presentation is below. Much of it will be familiar to readers, but are a few notable items in it. One is Zynga’s own user growth numbers, in graph form. The company has now reached 50 million daily active users, with a big uptick happening around the end of 2008.

Another item is the conclusion of a virtual goods charity drive within the game FarmVille, which we’d covered in more detail last week. A virtual good plant seed in FarmVille generated a total of $830,000 in a couple weeks, with half the revenue going to nonprofits working in Haiti.

“Don’t believe this will end with Facebook,” Pincus said yesterday. “You will see many other forms of social plumbing emerge, and the category of social apps will be up for grabs in every traditional sector, from travel to search to gaming.” What he means, as you can see more about in the slideshow, is his definition of “web 3.0.”

He defines the first version of the web as being about initial experimentation with web pages and links, the next version being about Google’s search and advertising efforts — essentially, successfully using the web as a platform to build a big, useful business. The third version of the web is the social application economy.

Here’s the slideshow: