A few things I’ve stumbled upon recently:

The Space category at Social Wallpapering. If you are even remotely interested in astronomy, space or sci-fi, you must click on at least a few of these great images. Social Wallpapering seems like it’s worth browsing, too. (This is the first I’ve seen it.)

The Wooden Binary Marble Adding Machine. If you’re impatient or just disinterested, scroll to the bottom and watch the YouTube video. Mesmerizing stuff, ladies and gentlemen. Well, assuming you’re geeky enough.

A couple of Linux alternative software sites: The Linux Alternative Project and Open Source Alternatives. Both provide links to Linux software that can be used as alternatives for some popular Windows-only software.