StumbleUpon top 5 rated websites: Secret knock detecting lock, best photoshop tutorials

A look at this week's top-rated websites from StumbleUpon, recorded on November 6.

This week's selection includes a website that shows you how a secret knock-detecting lock works, a website that shows how clever dolphins are, a website featuring an article about beauty and perception, a website showing how to make a caramel Apple Cheesecake Pie and a website that hosts the best Photoshop tutorials for July 2009.

1. Made by Steve Hoefer

2. Deep thinkers | Science | The Guardian

3. Perception & Bits Of Wisdom

4. Caramel Apple Cheesecake Pie & Annie's Eats

5. Tutorial Magazine - 32 Best Photoshop Tutorials of July...