The event was held inside Twitter's huge new headquarters building, which is still under construction. It was the first time the public has been allowed in.
It's so new that they had to get AT&T to run an Internet connection to the building just for the event. CEO Dick Costolo joked that they turned the heat off to make all of us blog faster.
More seriously, Costolo noted that the building has plenty of room for expansion -- and have no doubt, Twitter is going to hire a lot more people in the coming years.
Here's what we saw....
Here's the building -- a huge Art Deco piece. Workers were busy sprucing up the stone face on the front.
Matt Rosoff Business Insider
The building still has the old name on the front: Western Furniture Exchange. The neighborhood is a little bit sketchy.
Matt Rosoff Business Insider
But inside, the lobby is grand.
Matt Rosoff Business Insider
Don't get off here!
Matt Rosoff Business Insider
Take the elevator the 9th floor -- one floor from the top.
Matt Rosoff Business Insider
The elevators across the hall aren't working.
Matt Rosoff Business Insider
Here we are: a makeshift press room.
Matt Rosoff Business Insider
Lots of people milling around. It looked pretty well finished, in that warehouse-startup kind of way.
Matt Rosoff Business Insider
Twitter cofounder Jack Dorsey and CEO Dick Costolo explained that the building was built in 1937 -- the same year as another famous Art Deco structure, the Golden Gate Bridge.
Matt Rosoff Business Insider
They talked for about a half hour. Then we were invited to check out the new Twitter on a whole bunch of devices sitting around the room.
Matt Rosoff Business Insider
Nobody was at the iPhone table, so we took a look. Twitter's IT guy explained that they had to make a special deal with AT&T to get them to turn on an Internet connection. Then they had to cajole somebody into running cable up to the 9th floor.
Matt Rosoff Business Insider
It worked -- that's my live Twitter feed. Links to the new @ and # screens are at the bottom.
Matt Rosoff Business Insider
Jack Dorsey stuck around to answer questions. He seemed pretty proud of what the team had built.
Matt Rosoff Business Insider
After that, we wandered toward the purple light next to the elevators.
Matt Rosoff Business Insider
Not much to see now...
Matt Rosoff Business Insider
But by next summer, it's going to be a gorgeous cafeteria. Twitter told us that building is going ahead of schedule.
Matt Rosoff Business Insider
Good bones! There will probably have to be some earthquake retrofitting, though.
Matt Rosoff Business Insider
Another big empty space. This will be offices.
Matt Rosoff Business Insider
Here, they put up a placard detailing what the landscaping outside will look like.
Matt Rosoff Business Insider
So what about the view?
Matt Rosoff Business Insider
Pretty sweet. That's City Hall. It was built in 1899.
Matt Rosoff Business Insider
Another nice view toward the ocean.
Matt Rosoff Business Insider
And here's the view toward downtown.
Matt Rosoff Business Insider
Now check out what a REAL startup headquarters looks like...
Matt was an executive editor at Business Insider who ran the San Francisco bureau and oversaw technology coverage for Business Insider. Previously, he was an analyst for Directions on Microsoft and blogged about music tech for CBS Interactive. From 1995 to 2000, he was a founding editor at CNET.com.
