WikiRank [wikirank.com] shows a series of sparklines to denote those Wikipedia articles that are the most read, and those pages that are gaining in popularity. In addition, one can explore each article's detail page via search, which includes an article excerpt, traffic numbers and a web-embeddable traffic chart that compares the relative popularity of up to 4 other topics.
As you can check on the embedded chart below, one can learn how, on average, "information visualization" has been visited 3,840 times in the last 30 days, versus the 3,721 times "data visualization", and 4,212 times "scientific visualization". More interesting explorations might reveal the importance of news events, such as a sudden death of a famous person or the opening of a recent movie.
See also Google Trends Aggregator and Trendrr. Alternatively, see also Wikipedia History Mosaic, Most Visited Wikipedia Pages, Chromogram Wikipedia Editing, History Flow, Wikipedia Treemap and Wikipedia Clusterball.