For people in sfbay, you should really go to the Computer History Museum (http://www.computerhistory.org/ http://www.computerhistory.org/ ). They have a workin

For people in sfbay, you should really go to the Computer History Museum (http://www.computerhistory.org/ http://www.computerhistory.org/ ). They have a working model of Difference Engine No 2 -- one of only two in the world. The story goes that some museum in London was attempting to build one and ran out of money. Word of this eventually made it's way to Nathan Myhrvold, who offered to donate the required funds iff they built him one. Nathan has kindly loaned this mechanical computer to the museum only through the end of the year, whence it will go to his living room. The difference engine can calculate 7th degree polynomials with 31 digits of accuracy, and includes a mechanical printing press! They also run it every day at approximately 2 pm. It's well worth your time to go check out; the machine itself is beautiful. Video of the back right here (that's a mechanical carry bit!) http://www.youtube.com/watch?v=zbG8jUYJonM&feature=player_embedded http://www.youtube.com/watch?v=zbG8jUYJonM&feature=playe...