Physical whiteboard in the same room.
Big screen.
A command line (Terminal on mac, cmd.exe on windows).
A launcher app (Quicksilver on mac, Colibri on windows)
An editor (TextMate in mac os, NetBeans in windows).
A mindmap editor for planning, design and notes. (Freemind, cross platform)
(I purposefully stay cross-browser, cross-OS, going back and forth between my MacBook and my Wintel desktop pc. This forces me to keep using and testing both my product and dev environment in several different OS'es and browsers - plus it provides redundancy; if one env blows up in some way, I can just fall back on the other.)