2 screens = more work done?

I’ve just dug out an old 15″ flat screen monitor from a box and plugged it into my MacBook:

2 screens

The way I have it set up is to have email and twitter on the flatscreen, while having the actual work I am meant to be doing on the macbook screen. I’m finding it certainly helps my concentration to keep the comms stuff to one side!

Anyone else work with two (or more!) screens? How do you have yours set up?