You are on the road with your ultra-portable with its resolution impaired screen and you need a little bit more space to work on multi-documents (particularly Excel!) and you are stuck as this office (or hotel!) does not have a spare monitor to either use as your main screen or extend your desktop. So what do you do?
Well you may have heard of Display Link, it is a set of technologies implemented into hardware and software which allows you to hook up a second (or more) screen to a laptop over USB. This is good where you are port constrained, or where you have a docking station implementing the technology which then allows you to hook up using only one cable – the USB. Well they have now come up with an alternative for those who also travel with an iPad. They have released an iPad app that, in conjunction with software on your PC, allows you to use the iPad over WiFi as a second screen.
Now that sounds a bit screwy but it actually works in a passable way as long as you are not looking for a really dynamic display or trying to handle video. It is generally good enough for document editing and creation but it does have some noticeably lag and screen corruption when the screen is being updated. Of course, there are some other downsides.
Firstly there is a small processor bump on the laptop. Secondly you have to be on the same WiFi network which if you do not have access to WiFi is going to be a killer. Thirdly, if that WiFi is a bit poor or congested then the connectivity to the iPad is not maintained leading to freezes or disconnections. This is an early release of the software so maybe it will improve, but they cannot make up for the lack of good wifi. Note that these issues are because it is a software solution running over WiFi, I have heard good things of DisplayLink hardware solutions connected via USB.
All in all, if you have no other choice and you need the real estate, and you can give it the bandwidth then it is a workable solution. You are always going to be better off with a full proper monitor.
The App is available from the Apple iTunes store for £1.19/$1.99 (introductory price)