X is for ... not that many things. I did my best to find ten interesting things.

01.  X-rays:
 I know, this one is obvious, but how great are they?  They can not only see bones but also foreign objects and some organ issues.  All it takes is one semi-safe click, and it's done.  No shots, no IV, no drinking cups of slop -- just staying still and a click.  It's too bad all imaging isn't so easy.    

02.   Xantham Gum:
Xantham gum is usually used as a thickener for things like salad dressing and chewing gum, but it has a much more important function.  Over 2 million people in America are unable to eat gluten containing grains like wheat, rye, and oatmeal.  In order to make any king of bread like product from the loaf of bread and bagels to pancakes and tortillas; you need the protein known as gluten.  It works a bit like gum (no pun intended) to hold all of the product together and to give it the characteristic chewy flavor.  

For those that can't process gluten, it can be difficult to find basic products that many of us take for granted.  Imagine having a small child that has to be told that there is no cookies, bread, pancakes, cake, muffins, etc. any more.  There are a few products that are also used, but most products and mixes for the gluten free among us work with Xantham gum.  It is a corn based product that becomes very gooey and slimy when wet.  When used in your bread products, it won't be the same texture as the products you may be used to, but it is pretty good.  I actually found the cakes, muffins, and cookies to be better than those with gluten containing variety.  It is much more expensive than the regular product, but if that is what you need, it is better to have a little than nothing.  

If you have to also be on a corn free diet, you cannot use Xantham gum, but there are a few other products that can be used.  However, besides that sub-group, Xantham is the thing!

I used to be the inventory manager at a small gluten free catalog company.  We were small enough (until right before I left) that we hand bagged everything.  Xantham gum comes in 80 pound barrels, and it is as light as corn starch.  As you bag, it floats up and coats everything.  You have to be careful walking after this, because if you step on anything wet, it's going to be like hitting ice.  I guess, this is a good show of it's viscosity.   

03.  Xmal Deutschland :  
Xmal Deutschland is a goth rock band from Hamburg, Germany.  They were founded in 1980.  This is my favorite of their songs.
 

04.  The X-Files:
One of the best sci-fi series ever written, "The X-Files" pulled in people from every age, race, and culture in America, even those that didn't care for sci-fi.  It has spawned two movies, novels, comics, and music.  It has also been responsible for several well known catchphrases, some appropriated from other sources ("The truth is out there."). 

05.  Xanax:  
Xanax... hmmm...  Whpreo doesn't like to feel more calm and a little sleepy when they're really anxious?  Uh, I can't really think of much more to say on the subject.  Xanax is a good thing. 

06.  Xenophobia:
This is why I didn't say "10 Cool Things".  Xenophobia is the fear of strangers and the fear of immigrants.  Xenophobia has effected our country (and I would guess, all others), since it formed.  There is always one nationality or culture that a majority of the people is afraid and mistrustful of.  Now, it is those from the Middle East, before that, it was the Africans, before that, the Russians -- you get the idea.  It is a truly horrible thing for someone to be judged because of their genetics or because of the group they are associated with.  Other than those with an actual phobia (on an individual basis), it is a national phenomena of fear based on what everyone surrounding is afraid of -- a mass fear, almost bordering on hysteria.  Businesses are closed, people are raped, people are murdered ... all because there is a learned fear by society.   

07.  Xylophone:  
The xylophone is a musical instrument, originally made of wood that assigns each tab a musical note.  Mallets are played in succession to create music.  There are many forms, from the Western world, Asian, India, and Africa.  Here is a cool  video of someone playing "Flight of the Bumble Bee" on a marimba (an African xylophone).  


08.  Xweetok:
This is a species of pets from Neopets.com was released in 2005.  "Originating from the forests of Neopia, they make their homes in hollowed out trees and logs, and are quite agile. Xweetoks enjoy being chased, and often indulge in games such as 'Tag' or 'Hide 'n' Seek' with others of its species."  
My favorite is the Halloween style, pictured below.  If I got to have a sixth pet, this would be the one I wanted.  :)

09.   X-men: 
The X-men are a team of super powered mutants, led by Professor Charles Xavier.  It was created in 1963 by Stan Lee and Jack Kirby, in a way to give a more palatable medium to show the realities of racism.  In this case, the race being abused were the mutants.  Xavier gave them a safe home and place to learn to control and better use their abilities, eventually training them to protect the world from mutants who wished it harm.  It has sense spawned countless comic spin offs, cartoons, and movies. 

10.  "X Marks the spot."
"This cliché is from the earliest days of newspaper photography where the scene of the crime would be shown with an X to mark where the deed was done. It goes back even further in romantic accounts of such things as pirate treasure maps. The expression was being used joe-kingly by the 1920s, and now can be found as a formula phrase."
Source:  http://www.joe-ks.com/phrases/phrasesX.htm