The Guardian has created a interactive guide that enables users to explore and discover the hundres of thousands of diplomatic cables. Search via the map by "originating country" or "countries referenced" as well as by keyword searching.
This search interface will allow you to search cables emminating from the US Embassy (and consulates) in Canada. This page also features a common word visualization.
Data Visualization is essentially the process of taking information (whether its statistical or textual) and presenting it in a clear, graphic and easy to interpret manner. Many contemporary media outlets have taken to using Visualizations to better convey information to its patrons.
Use this link to go to an infographic created by El Pais. The map breaks downs the diplomatic cables by location and date.
This links to the super rich site provided by The Guardian (of London). In addittion to multiple infographics and visualizations, there are links to data sets available.
This motion infographic from Der Spiegel tracks the documents by "degree of classification" over time.
This flickr. photoset by blprnt_van are created using word frequency.