I have a dual monitor setup with a pretty old (2007-era) hardware: Intel E6750 CPU, 4 GB RAM. My latest upgrade to an Intel 320 Series, 120 GB SSD as the system drive makes this PC bearable. I also have bunch of HDDs for storage and archival. I am using a Microsoft Natural Ergonomic Keyboard 4000 and loving every minute of it. I've recently switched to a Logitech MX Revolution mouse after my Razer Habu died. I didn't quite like the middle clicks of this new mouse at first but got used to it. On the other hand, I've loved the programmable buttons on this mouse, using them for playing/pausing music, answering Skype calls, etc.
I am using a Sennheiser MM 100 Bluetooth stereo headset primarily for Skype conversations and have a love–hate relationship with it. I love its being a cordless gadget but I hate when I am having connectivity problems. My speakers are some very old Creative Labs Inspire 4400 4.1, I love the hardware remote volume control of this device which makes it really easy to adjust the audio.
I have two 23" LCD monitors, a Dell UltraSharp U2311H and a Philips 230C. I have a 22" TV mounted to the wall above my monitors. An HP Deskjet D1560 printer is connected to my PC but I can't recall the last time I've used it.
All my desk, bookcase and chair is bought from IKEA. Desk and attached bookcase is IKEA Expedit with lots of shelves. The chair is IKEA Markus, it is no Herman Miller Aeron but looks quite nice, comfortable and has a mesh material for the backrest.