I prefer to use OS X or linux on my laptops, and linux on my workstations and servers. Serious coing got spent on a 17″ MacBook Pro for most of my work and fun. I run Fedora on all my desktops and web/mail servers. There are many other distributions, some are fine, a few are excellent. I support a significant number of Windows OS variants; Windows XP sp2 is my current favorite offering from MS.

Software tools:

OS X specific
Quicksilver - something I can not explain and can not live without.
Vim - the editor. Not really specific to any OS but…
OmniGroup - authors of OmniWeb (my favorite THE BEST browser) along with many other fine tools.
Panic - Portland-based development company that makes second-greatest file mover in the form of Transmit, as well as my favorite web code editor (outside of VIM; heck, their CSS tool alone is worth the price of admission) in the form of Coda. And they make my desktop purdy with CandyBar. I have not met them, but I think these guys are SO cool.
Adium - chat away.
Vienna - read news, change the way you browse the web. I made a FlatGraphite style for Vienna that suits my tastes.

Stuff I use on Linux as well as OS X
GNOME - my favorite GUI for a long time, but now plays second fiddle.
Vim - didn’t I already say THE editor (worth saying twice).
rsync - the greatest file mover.
Gimp - a fine way to manipulate images.
Bluefish - excellent web coding tool.
Evolution - a decent email client for GNOME, though mutt is the best.
Inkscape - vector image tool.
AbiWord - easy, lightweight, cross-platform word processor.
Gnumeric - easy, lightweight, cross-platform spreadsheet.
Gaim - chat away on OS X or Windows.

Most of my web coding work is done with PHP.

Things to do in and around PDX: