Technology in Oz

I know there's always a lot of discussion about the time setting of Wicked. Everyone has their own opinion on the time period, the technology, the fashion, etc.
And honestly the book and musical don't give us a lot to go on. I've stated before the theory I use when writing my own Oz fiction- The Wizard of Oz was released 1939, which is Act 2 of the musical. I figure there were about 2 years between Acts 1 and 2, which would mean that Elphaba and Nessarose began Shiz in the fall of 1936-37 (I say '36 because I like to think some time passed between when they started and then Fiyero turning up, and the Lion cub, etc).

I was reading an article today on Cracked.com about 5 simple problems technology should have fixed by now and I was amazed to read that the fax machine was invented in 1843. Which means, by my timeline, there's every chance that Elphaba and co could be sending faxes to one another. That got me thinking about what other technology I never considered could be in Oz.

Here's some of the things I found:

• escalator (1900)
• vacuum cleaner (1901)
• air conditioner (1902)
• motion pictures (1910)
• pop up toaster (1919)
• notebooks with spiral binders (1924) [I know, right?]
• FM radio (1933)
• stereo records (1933)
• drive in movie theatres (1933)
• photocopier (1937)

There's also stuff like frozen food, instant coffee, self-winding watches, crayons, cellophane and even Monopoly. It's funny how you don't realise how old little things in life are until you actually look them up.