Imagine if no matter what country you visited, no matter what the culture, you could understand everything the indigenous people were saying. It sure would make traveling easier. Take that thought to another level like say, if you were planet hopping like the crew onboard the Enterprise. Fortunately for Captain Kirk and his peers, they had a universal translator.
The characters in "Star Trek" relied on a small device that when spoken into, would translate the words into English. Guess what? The technology exists for us in the real world. There are devices that let you speak phrases in English and it will spit back to you the same rhetoric in a specified language. The only problem is, these devices only work for certain predetermined languages.
A true universal translator like the one on the show may not be a reality, but the technology is available. Voice recognition has advanced considerably since its inception. But computers have yet to be able to learn languages. Computers would be able to theoretically gather the information much faster than a human brain, but a software program is dependent on actual data. Someone has to take the time and expense to put it together and make it available, which is probably why these systems focus on more popular languages.