Yes, if you want to know who visited the Twitter's New San Francisco Office Today (or any moment); Just head to Twisitor. Twisitor knows Who visits Twitter’s San Francisco office any moment.
@Twisitor, is a fun Twitter account created by Twitter guys for a fun project, during one of Twitter’s quarterly hackweeks.
There’s a camera in the lobby of Twitter’s new San Francisco office and it will snap a photo of anyone who visits the Office and stands in front of the camera. As soon as the Camera clicks the photograph of the visitor, a tweet goes out from the Twisitor account.
Twisitor is spreading the word about Twitter San Francisco Office visitors since January 11, 2013.
Recently these people stood in front of the camera at Twitter's San Francisco Office:
Twisitor knows Who visited Twitter’s San Francisco office Today