Google has some pretty neat built-in tricks, and it seems they've just added another one: with just a quick search, Google will try to tell you the release date of any movie or video game.
Just like the other tricks, Google does everything automatically. Just search for a movie or video game and add the words "release date" to your search (e.g. duke nukem forever release date) and it will try to guess the release date based on information around the net. By default, it will just tell you what web sites have mentioned the date that led it to its conclusion, but you can click the "Show Sources" link to see individual articles that mention the date.
Right now it seems to only work for movies and video games, but this could be useful for all sorts of things — especially when you're trying to track release dates that keep changing (I'm talking to you, HTC Thunderbolt). Remember, too, that you can avoid these automatically generated results by adding a comma to the end of your search terms, too.