In the beginning, there was MP3 sharing. Then came friend sharing (MySpace), photo sharing (Flickr), and video sharing (YouTube). Now it has come to this: PowerPoint slide sharing.

SlideShare.net offers a place to upload, view, and search for PowerPoint presentations. And since opening up its beta site in October, it has received tens of thousands of files.

The site's "decks," as the slide shows are called, are diverse: conference presentations, classroom lessons ("Let's Learn Colors!" from a middle-school Spanish class), and PowerPoint satire (Abraham Lincoln's Gettysburg Address famously summarized in bullet points, created in 2000 by Peter Norvig, Google's research director).

Site co-founder Jonathan Boutelle came up with the service while organizing a conference. It will hardly grab as many eyeballs as YouTube, but corporate firewalls won't block the likes of "Let's Learn Colors."