Some places list today as National Martini Day and others list it as National Dry Martini Day. In either case, I'm of the mindset of "Hard liquor only on Fridays and Saturdays and other days where I don't have to get up extremely early the next day" which means I'm not partaking in celebrating today's food observance.
Don't get me wrong - I enjoy a good martini or two. (Two's the limit for a lightweight like me.) In San Diego, Martinis Above Fourth is great place for a creative martini. In Las Vegas, I love hitting up Paymon's Hookah Lounge during happy hour. If you're looking to make your own martini at home, MartinisOnline should be the first website you pull up for tips and recipes. Although, I must admit, I am impressed with the amount of random martini facts on this page.
So what'a dry martini and how is it different than a normal one? Well, martinis are just vermouth and gin. (And a garnish, of course.) If you order a "dry martini," you're basically taking a crapshot, according to this thread on Chowhound. According to Wikipedia, these days a dry martini refers to the ration of gin to vermouth - the more gin there is, the drier the martini. According to Kevin Marsh, Hemmingway liked to order his in a 15:1 ratio. I shudder to even think about the taste of that! And according to the Jerasulem Post, a dry martini is made with gin and vermouth and called a dry martini to differentiate it from a vodka martini (you guessed it - a vodka and vermouth mix.) I've always been of the opinion that if someone asked for a martini (no flavors, no cutesy names, just a martini) they would get a drink made with gin and vermouth, garnished with either onions or olives. I always go for the olives in a plain ol' martini. If it's one of the fancy-schmany, creative martinis, I like it with a sugared rim or fruit.
The history of the martini is a little muddled. (Sorry, I couldn't resist.) Some claim it was invented in New York, and others claim California. And yet, others will claim it's a British drink. Well, wherever it was invented, you can pretty much order one in any place with a liquor license in a variety of flavors and with a variety of garnishes.