I am a laptop-worker. At our office I have access to additional displays, but otherwise (and mostly anyway) it's just me and my laptop. Or more precisely: me, my laptop and my iPad. I have used the iPad to read .pdf documents and other documents that I can store in my Dropbox and then open in the iPad. But yesterday I took my iPad-extension to a new level by installing the Air Display app. It's great!
How it works, is that you need the Air Display app on your iPad (costs approximately 9 euros here) and then you need the Air Display app for the PC/Mac. When using Air Display, both devices need to be on the same WiFi network and obviously the iPad app needs to be running. In Windows, the application creates an icon in the icon tray, and once the requirements of WiFi and app running on iPad are met, you can connect to the iPad (good insturctions are included in the the iPad app).
I started my journey to be an Air Display user by installing the app on my iPad, and when I then tried to get the software for my Win8-running laptop, I had a moment of disappointment. After installing the PC application, it told me it did not support Win8, and then it crashed.
Avatron however is working on a Win8-supporting version too. It is still in beta, but if you're not scared of betas (which I am not) and are willing to participate in the beta-testing, Avatron offers the beta drivers for (test) usage. So that's what I did. I asked for the beta version for Win8 and ok, the screen flashes sometimes with some operations (like e.g. changing the orientation of the iPad) and it has some issues with Office2013 (e.g. trying the slideshow in PowerPoint 2013 on iPad resulted in PP crashing, and as a little bit bigger problem, Lync 2013 started crashing when joining an online meeting).
The normal mouse moves to the iPad screen, the laptop keyboard works as well. According to Avatron, all of the Win8 gestures are not there even though it is fully touch compatible also; I mean, it is an iPad. But since I'm using a non-touch laptop, my hands are on the keyboard/touchpad so their usability on the iPad additional display is the key feature for me.
Waiting for the RTM :)
[Edit: April 25th, 2013 I just noticed that AirDisplay is not beta anymore!]