Textmate or vim for text editing
Firefox for webbrowsing
Extensions: Vimperator, Vertical Tabs, 1Password, LeechBlock, NoScript, Adblock Plus
1Password to track passwords, integrated with Dropbox to sync iPad/iPhone.
Git for version control
Indefero for Google Code-like project websites
nvALT for scribbling notes down that are persistant across system crashes.
Alfred for wicked-fast apple-space searches
MacBook Pro - roundabout machine
Homebrew Core2Quad machine - runs radio stuff + smaller numerics experiments
work machine: dell dual Xeon X5560 machine, 32gb ram - runs larger numerics experiments
linode machine - hosts this website, several others, source code trees, etc