PBase has a cool feature where you can search by lens. I searched for a few I was interested in, and came across some amazing photos taken with Canon’s 24mm Tilt-shift lens. Tilt-shifts are weird, and descriptions of them are either very basic (first sentence on the Wikipedia article), or very complex (involving the Scheimpflug principle).
I came across one particularly neat gallery. Tilt-shifts are known for two things. One is that you can use them to correct the ‘distortion’ where lines seem to converge. Check out this photo as an example, and another. Notice how nice and vertical the lines are? Compare it to this one, which is still a neat photo, but notice how all the building seem to ‘slant.’ (And an extreme example: it becomes more pronounced at wider angles.)
As an aside, since all my photos were to this one neat gallery, I’ll point out some that have nothing to do with tilt-shift, but are just cool. This one is one of the more brilliant uses of unusual angles. (It’s the same concept as some other photos I saw once, which was done on ice/snow for an even cooler effect.) It’s really pretty remarkable. This one is cool, too. (And another.) Here’s a great one of Boston Harbor. And here’s one showing how cool a 12mm lens is. I think it saw some post-processing, but this one is really cool, too. Ibid.
But my favorite, by far, is this set of Logan. Last time I flew into Logan, all I could think was, “Wow, this would be a great spot for photos.”