Numerous "Stranger's Guides" written for 19th Century tourists can be found on the Internet Archive. A sample: New York (1828). Boston (1857). Washington DC (1884). Montreal (1872). London (1828). Paris (1822). United States and Canada (1838).
British market-research firm Ipsos Mori has released the results of "The largest ever global study of the best city to do business in, live in, and visit." Interactive data here, more info here.
"Thanks largely to smartphones, this is probably the best time ever to live in a packed city... Steve Jobs was a lifelong suburbanite, but it turns out he perfected the city." [google cache for those getting a log-in page.]
Paris versus New York. A friendly visual match between those two cities, as seen by a Parisian-based-and-lover on New York : details, cliches and contradictions.
8bit Cities: Amsterdam - Austin - Berlin - Detroit - London - New York - Paris - San Francisco - Seattle - Washington, D.C.
The Vertically Inclined Photographer: Shooting Paris, Rome, the French Riviera and the Loire Valley from a low-flying plane is Patrick Durand's photographic obsession. It's an interesting flat alternative to Horst Hamann's [click on "Gallery" and go to "New Verticals"] tall vertical New York. There's something very exciting about looking at familiar sights from an unfamiliar point of view. [Both sites very, perhaps too Flash.]