The Tumblr redesign is gorgeous all around, but the attention to detail in the animations of the photo picker is especially delightful. Subtle & understated, but those easing curves make you smile every time.
Matt Davenport and Alex Penny have released what looks like the first of three apps under the name 'Simple'. This microsite for their Currency app is very simple indeed, with playful animations and rollovers.
Giving a window of context to the content, Ways of Knowing Cities a research project by Center for Spatial Research from Columbia University uses google street view and transparency to form an interactive background.