A thoroughly addictive use of the Instagram API (along with Node.js and Socket.io): see a montage of images being taken in a city right now.
Some future-friendly musings on mobile from Mozilla and Yahoo.
A very clever and tricksy way to sync up multiple devices so that when you refresh a URL or follow a link on one, it happens on all of them. It uses OS X’s Internet Sharing feature combined with locally-hosted Node.js. It’s positively McGyverian!
A collection of network diagrams and visualisations from the simple to the sublime.