Are there any superstitions you still 'believe' in?

[NuttyFluffers]

19. crap, there's a lot i do, now that i think about it.

knock on wood.
salt over the shoulder.
no knives as wedding gifts (learned that one the hard way -- receiver divorced).
mirrors -- and elephants -- near the entrance door (keeps away misfortune).
don't share good plans until it happens (even those who love you may unconsciously think ill and sabotage your fortune).
open a window of the recently deceased (to let the spirit free and not linger).
new ant invasion is herald of good luck (but we get rid of them anyway).
1st spider of new home is good luck.
no chopsticks sticking straight out of your rice (invites thoughts of death because that's how rice bowl is presented to ancestors).
how far up you hold your chopsticks determines how far away you'll live from home.
throw the horns upon ill fated omens or gross misfortune crossing your path.
pray for the dead when driving by the cemetery (or car accident).
horseshoes, calligraphy of Allah, crucifix, etc. by doorways to keep areas clean.
always eat your kimchi/veggies/etc. oh, and never waste food or one day you'll go hungry.
etc....

... but then my extended family and childhood neighborhoods have always been cosmopolitan. being exposed to a little of everything leaves me like the lint magnet of cultural taboos, customs, and superstitions. sometimes i have to ask myself is it just etiquette or is it just superstition.