several different graphs & animations showing how 2,147,483,647 web pages, deliberately ordered in a binary search tree, were monitored by different search engines, such as Yahoo! Slurp, Google bot & msn bot, over a time period of a year. each search engine's behavior was visualized as a tree image that represents which nodes were crawled: each line in the image represents a node, the number of times a search bot visited the node determines the length of the line.
by investigating the shape of the resulting tree over time, one can discover how the search engines are different in crawling the web.
see also yahoo versus google & search engine comparison.