“The ten principles that contribute to a Googley user experience.”

1. Focus on people – their lives, their work, their dreams.
2. Every millisecond counts.
3. Simplicity is powerful.
4. Engage beginners and attract experts.
5. Dare to innovate.
6. Design for the world.
7. Plan for today’s and tomorrow’s business.
8. Delight the eye without distracting the mind.
9. Be worthy of people’s trust.
10. Add a human touch.

Definitely read the full details here:

http://www.google.com/corporate/ux.html