When you glance at it, it looks like Facebook. A lot. But, unlike your Facebook news feed, it's a one-page shop. If your friend posts a Picasa album, for example, thumbnails appear, but if you click on them, it won't pull you into another page or browser window; instead, a photo-gallery overlay appears over the entire browser window, images are blown up to full-screen size, and a small navigation pane lets you scroll and preview other snaps in the album. The same goes for YouTube embeds, but that's old hat by now.