The Map of Physics : "Everything we know about physics - and a few things we don't - in a simple map." (SLYT, via Kottke)
Paperscape is a searchable 2-dimensional visualization of the 800,000+ scientific papers (mostly in physics and math) on the arXiv preprint server.
whitney music box -- a fantastic animation
You may notice some interesting links between the visuals and the audio, especially if you are a musician. For example, when the pattern forms a 3-arm starfish, the chords you are hearing are diminished chords, which consist of minor thirds, an interval in which the notes are 3 chromatic steps apart. The chords you hear always bear this type of relationship to the pattern you are seeing, consisting of intervals which match the arrangement of arms.Really, just look, and you'll get it. [more inside]
Gorgeous images, selected solely for their artistic appeal, from the pages of Physical Review B.
Proofs and Pictures: The Role of Visualization in Mathematical and Scientific Reasoning [video] "The picture is a telescope for looking into Plato's heaven." -- James Brown [cached]