Even if you don't care much about how translators work, you do care if they're easy to use and carry. You'll want to consider the following basic specs while shopping for electronic translators:
Battery requirements -- OK, two choices here. Many electronic translators run on two AAA batteries, so you'll be packing backup batteries. A few models come with a lithium-ion rechargeable battery (like the one in your cell phone or tablet). They last longer than single-use alkaline batteries, but they cost and weigh more. And you may need to pack adapters to use the device's charger, designed for U.S. power supplies, in other countries.
Dimensions -- Most translators with a fold-up screen, like the Franklin Electronics 14 Language Speaking Global Translator have a footprint similar to an iPhone (4.5 inches by 2.3 inches, or 11.4 centimeters by 5.9 centimeters) when the display is closed. The ECTACO iTRAVL Speech Translator is a bit larger, coming in at 6 inches by 3.2 inches (16 centimeters by 8 centimeters). You could stuff either device into a shirt pocket, although you run the risk of looking like a tourist.
Weight -- If you're looking to lighten your load, evaluate the weight of electronic translators carefully. Some weigh in at about 4 ounces (less than an iPhone), but others are twice as heavy. And the Lingo eTERPRETER 12-Language Talking Translator tips the scales at a full 2 pounds (0.9 kilograms), which could really slow you down after a long day of sightseeing.
Display -- Most basic electronic translators come standard with backlit, black-and-white LCD screens. Even if their translations excel, these devices can feel like old-fashioned calculators. If the visual presentation of information is important to you, then you'll want to look for more advanced translators with color screens and even touch sensitivity. The ECTACO Partner 900 series translators boast 3.5-inch (8.9-centimeter), full-color, touch-sensitive screens that allow user input via a supplied stylus.
Connectivity -- Not all electronic translators allow you to connect to a personal computer for data exchange, but some do. This is important if you want to customize the device's dictionary with your own entries. For example, the Franklin Electronics 14 Language Speaking Global Translator comes with a USB hub designed for a mini-USB 1.1-compatible connection. Once you connect the translator to your Mac or PC, you can download a personal dictionary of up to 500 words from your computer to the device. This is great if you're trying to communicate about a highly specialized subject area or if you need occupation-related words or phrases.
USB connectivity is also necessary on translators that second as audio players and e-book readers, as many ECTACO models do.
Don't forget the accessories, too. Many speaking translators come with earbuds or headphones, and a few throw in a USB cable. Optional carrying cases are also available for most models.