If you try it Houston, you'd never go back... I use my laptop and a 17" LCD monitor next to it. It makes this work so much easier.
So... if you have a laptop all you need is a monitor, if you have a desktop you'll need a second video card or a dual monitor video card. A single dual monitor vid card is going to be a lot easier to configure.
When you have two windows on one screen it's a constant compromise, with two monitors you open both up max, it's much easier on the eyes.
I also invested $30 or so in a swing arm mount for my monitor so that it's at the perfect height and angle. That sounds like a small detail that only a whiner would think about, but it actually makes a big difference too.