You love your new dual-screen setup at the office. The productivity enhancement is great. But you wish you could have the same benefit when traveling.
You can, and without lugging a huge AC powered LCD monitor with you. I recently acquired for about $70 a refurbished AOC e1649Fwu 16" USB monitor and tried it out on my last road trip. It fit neatly in my laptop bag, leaving plenty of room for my Microsoft Surfact Pro 3 and its keyboard cover (and all manner of cables, headsets, and other stuff I pack for my travels).
The monitor requires no additional power other than what it gets via the included USB cable connected to your computer's USB port. The specs indicate that the monitor will work with USB 2.0 or 3.0. I used it only with the single USB 3.0 port on my Surface Pro 3 and also with a powered Amazon Basics USB 3.0 hub (at least until the hub died prematurely - a replacement is on its way thanks to Amazon's speedy return and replacement policy). The monitor worked fine with the direct connection and with the hub. The long Q&A on Amazon.com confirms that it works just as well over USB 2.0 and is also Mac OS X compatible.
My Surface Pro 3 had no problem powering the monitor, even when running solely on battery power. The drivers load in Windows 8.1 automatically the first time the monitor is connected, but a quick visit to the AOC web site is recommended to download the software that allows the monitor to switch orientations automatically from portrait to landscape depending on how you want to use it. Portrait mode is great when working on Word documents. The integrated fold-out stand works in either portrait or landscape mode, but there is a noticeable backward slant in either orientation.
The 1366 x 768 resolution is nothing to write home about, but it is more than sufficient for Word documents when in portrait mode, Excel spreadsheets in landscape mode, and fairly static content like Outlook or Twitter in either mode. I didn't test it with fast-moving video since that isn't the purpose for which I purchased the monitor. Viewing angles are also not exemplary, but that could be an advantage when working in less than completely private locations.
I noticed that the AOC monitor was a bit brighter than I like, but there is no brightness level control (in fact, the monitor has no controls at all, just a port for the mini-USB cable connection and the fold-out stand. Fortunately, there is a free utiity called PangoBright that lets you control the brightness of any monitor, whether external or built-in. The brightness levels of multiple monitors can be controlled independently with PangoBright. I left the Surface's built-in display at 100%, but dimmed the AOC external monitor to either 60% or 80% depending on the ambient light.
There is a newer model of the AOC external USB monitor that has a slimmer profile, sleeker stand, VESA compatible mount, a brightness control, and a carrying case. The AOC e1659Fwu is also 16" and sells for $130 on Amazon.com. Either the original if you can find it for under $100 refurbished of the newer model at $130 is money well-spent for dual-screen productivity while traveling. If you buy the older model but want a separate carrying case, I discovered that the Targus Trax Laptop Sleeve for less than $10 fits it perfectly and has a nice zippered pocket to hold the USB cable.