If you're in NYC and have a camera: Today's the day the sun pays homage to Gothamites by having the decency to "land" exactly in-line with Manhattan's street grid at sunset, so it looks like a security guard shining a flashlight down a corridor. Cheekily dubbed "Manhattanhenge," the biannual phenomenon makes for some nice photos, even if they don't quite capture the effect of seeing it with your own eyes.
Manhattanhenge actually lasts for two days each time. On the first episode, today, the sun will line up with the grid just as it sinks to roughly 50% below the horizon:
For shooters looking to capture it, you want to pick your spot an arrive there at roughly 7:45pm, and be prepared to cool your heels for 30 minutes or so to capture your shots. You'll probably also need to mess with your exposure settings a few times to get what you want.
Lastly, don't be a dope and pick a street like 32nd, where east-west visibility is blocked by inconveniently-placed edifices. In general you can't go wrong with any two-way street where the subway stops—14th, 23rd, 34th, 42nd, et cetera. Have fun—and if you mess it up, you can try again on July 11th.