After a lengthy discussion with my mother about how common some of Shakespeare's phrases have become in our culture I did a google search for the phrase "all the worlds a stage" and with the advanced option asked it to exclude the word Shakespeare. I got 11,600,000 results. The hits were as varied as can be. There were blogs (like Joanna's but not hers), theatre groups, and ad for World of Warcraft, a book titled "All the World's a Stage", a NASA article about the movement of dust across the world, an announcement of an art exhibit for a museum, random news, a wiki-page for a book about Tom Cruise with "All the World's a Stage" as part of the title, and that's not even all the types of things that showed up on the first two pages. High-brow, low-brow, its a phrase that has permeated every level of our culture.
The painting is a James Christensen painting called "All the World's a Stage" and is one of my favourite paintings. I even liked it before I found that it also happens to be the first image that shows up when you search that phrase.
I also noticed today this line is very close and most likely the inspiration for the description Prakash Raj, one of the Indian actors I follow on Twitter, has for himself "The world is also a stage."