"Critical thinking is..."

From my travels online it is evident that people have very different ideas of what critical thinking is.
Some think CT is the same as scientific thinking. Others believe it is most important for citizens who are constantly bombarded by advertising, spin, and propaganda.
Some find it in debunking popular beliefs or pseudoscience.
Some define it in terms of formal logic, truth tables, and Venn diagrams--others in terms of informal logic and avoiding popular fallacies.
Some use the alleged lack of CT to bludgeon people they disagree with, even though their own argument is on shaky ground.
One concise definition of CT is this, by Richard Paul and Linda Elder in The Miniature Guide to Crtical Thinking Concepts and Tools:

"Critical thinking is that mode of thinking--about any subject, content, or problem--in which the thinker improves the quality of his or her thinking by skillfully taking charge of the structures inherent in thinking and imposing intellectual standards upon them."
(See more definitions at www.criticalthinking.org/aboutct/define_critical_thinking.cfm)

This puts the responsibility back on the thinker rather than the person the thinker is debating or making fun of. It emphasizes a conscious and perhaps continuous self-improvement. Is that too hard? Not enough fun? Does it give a full picture of CT?