In 1999, I paid $499 for a 19-inch, 1280 x 1024 resolution CRT monitor and thought I’d gotten the deal of the century. Today, you can buy a high-quality, full HD (1920 x 1080) screen like the 23-inch Zalman MZ230ED for as little as $120 at online retailers like NewEgg and Amazon. By attaching a large monitor to your laptop, you can double your workspace and increase your productivity by up to 50 percent.

Whether you put your email on one screen while you write documents on another, keep your Photoshop tools on the right display while the photo is on the left, or just use the second screen to play videos while you work on the main one, a second monitor is well worth its minimal price.