I’ve added favicons. Many thanks to /u/Aurnyx for the outstanding base design, and Nick (on IRC) for vectoring and exporting them in various sizes! The icon reads surprisingly well even at 32x32, so I’ve exported everything at that size, except for 16x16, where the symbol reads best as the dot and circle.
Note that this may not show up in many browsers until their cache expires and it tries to load the icons again.
Here’s a small sampling of the icon at different sizes: