Luke Wroblewski summarizes the fundamental principles that guide Google in designing user experiences, as told by John Wiley in a WritersUA presentation.

1. Useful: focus on people -their lives, their work, their dreams.
2. Fast: every millisecond counts
3. Simple: simplicity is powerful.
4. Engaging: engage beginners and attract experts.
5. Innovative: dare to be innovative.
6. Universal: design for the world.
7. Profitable: plan for today's and tomorrow's business.
8. Beautiful: delight the eye without distracting the mind.
9. Trustworthy: be worthy of people's trust.
10. Personable: add a human touch.

Hat tip to Frank for the link.