Sizes and scales

Disasters, spectacles, wars, and ancient landmarks: hearing or reading about the size of an event or place is nothing like seeing it for yourself. Recognizing this comprehension gap, the BBC has launched a project called Dimensions (howbigreally.com). Want to know how the moon's diameter compares to your hometown? Interested in seeing how much of Europe the Gulf oil spill would cover? Curious about how ancient Constantinople's size squares with Texas? Simply choose what interests you-say, the Great Wall of China-then punch in your zip code or the name of the town, and see an illustration laid across the map. (The Great Wall, by the way, would stretch from eastern Illinois to Canada's Prince Edward Island.)

The Dimensions project is an attempt to bring events and places in history into "human scale"-giving viewers a way to translate abstract knowledge into something more concrete. Currently, information designers in the BBC research department create the map illustrations using library and online resources, and the news organization plans to use the technology to illustrate its articles. But users will eventually be able to add their own illustrations-exciting news for teachers, pastors, students, scholars, and enthusiasts.

iSigning

One of the more widely touted features of the iPad is its ability to extend the traditional definition of the book, since the device's multimedia capabilities introduce the possibility of animation and sound into the reading experience. Taking this to the next level, the publisher iStoryTime recently released an iPad book that includes sign language. The book Danny the Dragon "Meets Jimmy," available for $3, includes the book's text and illustrations, a voice that reads aloud, and a video of a woman signing the story-useful not just for deaf children but also for students of sign language.

Checking in

Facebook, which added its 500-millionth active user in July, has a new feature enabling location-based updates, called Facebook Places. Using the iPhone app or a mobile phone with the latest web browser and geolocation capabilities, Facebook users can "check in" to a location. First, the phone locates the user and generates a list of places nearby. If the place isn't on the list, the user can add it. After tapping the check-in button, the user can see if any Facebook friends have checked in nearby. (Users may disable this capability in their individual privacy settings).

Location-based check-in is nothing new. Similar applications such as FourSquare already help friends to locate one another and share restaurant and store discoveries. Such applications extend the web's ability to stumble unexpectedly across something cool by helping friends "stumble across" one another in real life. Yet Facebook Places will likely overtake its competitors, given the site's massive, devoted user base. Check-in is currently only available in the United States, but global rollout seems imminent.