Eliazar Parra Cardenas’ new project Backbars doesn’t add any new information to a site. Its aim is to make it easier for your brain to make sense of the information that’s already there. And that’s essentially the name of the game for “information design” junkies like Cardenas.

“The whole point is to make textual information easier to absorb,” Cardenas, 24, told me over Skype from his temporary home in Madrid. “[A well-designed site] should maximize the information that a user can understand — that you can just glance at, or take note of -– without actively thinking.”

Backbars is a small script that only works in Firefox and requires the free Greasemonkey plugin. (GreaseMonkey is a useful tool that lets you customize the way web sites look or act.) It takes numerical data on web pages and turns it into subtle but easily readable bar graphs.

On the social news site Digg [left], for instance, it creates bar charts based on how many times a story has been “dugg.” On the community weblog Metafilter [above], it’s the number of comments users have left on a story. At the social bookmarking site Delicious, it’s the number of times someone has bookmarked the web page. The idea is that these small, unobtrusive graphs allow users to see how popular an item is by simply glancing at it — rather than searching for easy-to-miss numbers and having to recall seventh-grade ratio lessons.

Cardenas says that concept should be integral to the development of text-based sites. When people read online, they don’t read one word after another in a linear way; they “glance around, get the structure of it, jump to the beginning of paragraphs or to the links,” he said, making the well-designed presentation of quantitative data “very powerful.”

This is particularly important with regard to news sites, which have always been in the business of providing as much information as quickly as possible. “We’ve already tried the obvious in print: putting as much text as possible in one glance (hence broadsheets), mixing in images, headlines, columns,” Cardenas wrote in a follow-up email. “I think the next step will be digital developments like backbars, favicons, sparklines, word coloring, spacings.”

Despite a recent uptick in interest, Cardenas says he still considers most news sites poorly designed. Happily, he thinks an array of small, quick-fixes that make quantitative data more easily digestable — like Backbars, naturally — can go a long way in making the online version of magazines and newspapers better at what they do best: conveying information quickly. “The most interesting direction of information design is not flashy, blockbuster visualizations but subtle, ambient layers,” Cardenas wrote.

As a pet project last month, he redesigned the appearance of the The Economist‘s site. His very simple, streamlined version uses bar graphs to illustrate the length of stories. “I did it just for fun, but it’s gotten a lot of positive feedback from people who’ve seen it,” he said. “I think it just makes it easier to see quickly what’s going on. It’s straightforward.”

As for Backbars, 800 people had downloaded the script as of last Friday. Cardenas is looking beyond social news sites: He has released a version of Backbars for tables on Wikipedia, and this week he’ll release a version that works on eBay and Craigslist as a price-comparison tool.