The tool for highlighting EXPLAIN output is provided on <a href="http://explain.depesz.com/" rel="nofollow">http://explain.depesz.com/</a> (as mentioned in a later slide). It's commonly used when asking for help and discussing queries on #postgresql on Freenode.
Can also warmly recommend the EXPLAIN visualizations generated by pgAdmin: <a href="http://www.pgadmin.org/" rel="nofollow">http://www.pgadmin.org/</a><p>See an (simple) example here: <a href="http://www.pgadmin.org/images/screenshots/pgadmin3_macosx.png" rel="nofollow">http://www.pgadmin.org/images/screenshots/pgadmin3_macosx.pn...</a>
And I haven't completely finished my explanation of it! <a href="http://jimkeener.com/posts/explain-pg" rel="nofollow">http://jimkeener.com/posts/explain-pg</a><p>I love EXPLAIN, it's such an amazing tool for figuring out how to get a query to run faster. It's much more detailed than MySQL's and often one of the reasons I list when people ask if they should checkout/switch to pg (which you should!)
Another EXPLAIN documentation, probably easier to read since it's a PDF and not a slideshow: <a href="http://www.dalibo.org/_media/understanding_explain.pdf" rel="nofollow">http://www.dalibo.org/_media/understanding_explain.pdf</a>