ROSLIN

It seems that somebody uploaded the Da Vinci Code to his website so that now it is very convenient to copy and paste the needed paragraphs. So here is the famous excerpt about the Star of David from the Chapter titled ROSLIN:

The sanctuary was empty except for a handful of visitors listening to a young man giving the day's last tour. He was leading them in a single-file line along a well-known route on the floor-an invisible pathway linking six key architectural points within the sanctuary. Generations of visitors had walked these straight lines, connecting the points, and their countless footsteps had engraved an enormous symbol on the floor.
The Star of David, Langdon thought. No coincidence there. Also known as Solomon's Seal, this hexagram had once been the secret symbol of the stargazing priests and was later adopted by the Israelite kings-David and Solomon.

See: http://www.flickr.com/search/?w=all&q=Star+of+David+roslin&m=text

Sabra Cactus

Picture of Sabra Cactus Hexagram is courtesy of "maxnathans" who published it on Flickr and wrote to me:

The cactus in question belongs to the Cereus family. they grow meters high in my garden .
A few years ago a piece broke of because of stong winds, put the piece on the ground next to my garden and after a while, little plants started to grow and now as you can see they get bigger. The plants you can see are some years old . From the top they look like a Magen David really. When they get bigger they change a bit.

Pottery

Picture is courtesy of "Tobyotter" from Flickr who wrote to me:

MY father is Jewish and My mother was Catholic - So i was raised around both faiths. I always liked the Star of David - in pottery class I had a bit of clay left so I made this - as a reminder of Father.

Magic Stars

There are some kinds of hexagrams that have no religious connotation. One of them is used for mathematical calculations. Mutsumi Suzuki wrote an interesting article titled Magic Stars where he defines them and shows how to use them:

A six-sided magic star is constructed using 12 numbers, where all the edges add up to the same number
Edge A+C+F+H = edge A+D+G+K = edge B+C+D+E = ...

Healing All Disease

In Manly P. Hall’s book titled THE SECRET TEACHINGS OF ALL AGES, 1928 there's a paragraph about Dr. Sigismund Bacstrom who believed that if a physician could establish harmony among the Four elements, and unite them into the Philosopher's Stone symbolized by the six-pointed star - he would possess the means of healing all disease.  In Alchemy the Philosopher's stone is represented by a dot over the upper right hand point of the hexagram and this point is meant to represent the presence of God 

Beit-Hagefen, Haifa

Beit-Hagefen (House of the Vine)is an Arab Jewish Center that was established in 1963 to promote coexistence issues of Jews and Arabs and Christians in the northern part of Israel.

This picture was taken by me.

Sevilla Cathedral Spain

Sevilla Cathedral Hexagram picture is courtesy of "nirakara" who published it on Flickr and wrote to me:

As for the story on it I don't have too much on it, though if you search for the Cathedral of Sevilla you'll find it easily online. I think it's the largest in spain and like many of the larger churches in the south of spain it used to be a Mosque and was converted when the area was conquered. It gothic in nature and so in that way it uses a lot of visual detail employing all kinds of geometric symbols and wether this particular one was used with meaning is probably anybody's guess.

Building was begun in 1402, with construction continuing into the 16th century.