Andy Miller: Using Sublime Text 2 for Development (Rocket Theme)
Some good tips for getting started with Sublime Text 2 and using its many features.
HTTP Client
"A Mac OS X Leopard developer tool for debugging HTTP services by graphically creating & inspecting complex HTTP messages."
ies4osx
Run IE5, 5.5, 6, and 7 in OS X under X11 emulation. It actually works perfectly and installs in minutes with a few clicks.
Paparazzi!
Free Mac software for taking webpage screenshots. Can capture the entire length of a page (beyond the "fold").
urlgreyhot: OmniGraffle Wireframe Palette
An excellent resource for wireframing.