I usually have several tabs open in Safari in the background, and sometimes I see it taking up an unusual amount of CPU (PluginProcess or WebProcess).
How can I figure out which tab (or tabs) is causing this? If there are no easy GUI solutions, I'm also open to Terminal-based techniques for finding the culprit. I hope not to have to do this very often.
(Note: I realize this is similar to an old question, but Safari has been updated since then and perhaps there are new techniques available.)