Warren Buffett has joined Twitter.

Welcome, Warren!

If you've been living under a rock for the last few years, Twitter is a micro-blogging site where people can share a sentence or two of text at a time for the world to see. It's usually a link, or quote, or a statistic, or just a a quick thought.

Here's Buffett's first Tweet:

Brilliant. 

No one knows how much Buffett will be Tweeting, or what he might Tweet about.

But here's what we know: If the essence of Tweeting is to share smart, pithy -- and often witty -- one-liners, Warren is basically the original Tweeter. He's been making smart points while making people laugh for years. 

Consider some of our favorite Buffett quotes: 

On being active: "It's nice to have a lot of money, but you know, you don't want to keep it around forever. I prefer buying things. Otherwise, it's a little like saving sex for your old age."

On loving your job: "You want to have a passion for what you are doing. You don't want to wait until 80 to have sex."

On focus: "You know, if I'm playing bridge and a naked woman walks by, I don't ever see her."

On due diligence: "Other guys read Playboy, I read annual reports."

On over-diversification: "If you have a harem of 40 women, you never get to know any of them very well."

On internal yardsticks: "Would you prefer to be the greatest lover in the world and known as the worst, or would you prefer to be the worst lover and known as the greatest?"

On investing in 1973: "I feel like an oversexed guy on a desert island. I can't find anything to buy."

On investing in 1974: "I feel like an oversexed man in a harem. This is the time to start investing."

On the first stimulus package: "[It was like] half a tablet of Viagra and then having also a bunch of candy mixed in -- it doesn't have really quite the wallop."

On the speed of economic recovery: "You can't produce a baby in one month by getting nine women pregnant. It just doesn't work that way."

On financially transmitted diseases: "Derivatives are like sex. It's not who we're sleeping with, it's who they're sleeping with that's the problem."

You'll have no problem fitting in, Warren.