I'm always interested in the way other people work so I figured I would share my environment and what makes me most productive.
13" Macbook Pro. When I'm sitting at my desk I use a 23" external Samsung monitor, Apple wireless keyboard, Magic Trackpad.
OSX Snow Leopard. Firefox for web browsing. Sublime Text 2 for development. Git and HG on the command line for version control. CLI and PGAdmin3 for Postgres. CLI and Navicat for MySQL. Sparrow for email. Gtalk for IM. iTunes and Spotify for music.
I usually get up around 8:15am EST. Make some coffee (dunkin donuts), feed my dogs, and let them out. Then start working around 8:30am. I usually work until about 5pm with a 30 minute lunch break but depending on what's going on I might take a longer lunch and then work later.
I tend to move around a lot during the day. I find that a change of scenery really helps keep me thinking straight. I start the morning in the kitchen most days and then move to my office a couple of hours later for a scrum call. Sometime after lunch (if the weather is nice) I'll move outside or some random place in the house (living room, bedroom, kitchen, office). Whenever I start to get stir crazy I'll get out of the house and work from one of the coffee shops downtown.