I sort of have a two monitor set up.
I have an HP and the video card is not set up for dual monitors. I've looked into replacing the video card, and even though I have a college degree in computer tech I haven't banged around in a PC tower replacing stuff in a long long time. I'm concerned about fucking something up and it's just not worth the risk.
Instead, I bought a second all in one touch screen and have that on my desk top as well. I work off of my main PC, and my second computer, the touch screen, just runs my email. This way I instantly know when my email comes in, and I can just lick with fingers on the screen and delete crap I don't need, etc. It's been pretty handy.
Here's what my office looks like. From left to right I have TV/DVD combo, my main PC monitor, and on the right my touchscreen.
My next PC will be dual monitor. But for right now this is fine.