Here's an image I fond on historypin.com, a fascinating site that allows users to "Google Street-view" urban scenes the past via historical photographs. This picture shows my office in 1935. How amazing! It doesn't look much different now from how it looked then (other than the addition of a few Starbucks Cafes), and there are still plenty of people walking around the neighborhood sporting black fedoras just like in this picture - I guess styles really do come back around!
My office, October 7th, 1935
And while I'm on the object of time travel, here's a nifty website I found that maps the development of Manhattan through time.
An overlay map of New York showing topography, trains, ferries, zoning, and subway routes
Transparent New York
It's amazing to think that the whole island used to be just one big set of farms! Who would have guessed!