What is the longest 1×x brick ever released? Out of curiosity: How long can a 1×x brick be?

When there are differences, I can think of the following categories:


Longest brick ever included in a regular Lego set
Longest brick ever available through other channels
Longest brick produced ever and visible on exhibits or other occasions, but unavailable to the public


EDIT: I am only interested in bricks made by LEGO, clone brands do not count.
If you mean specifically Lego bricks, I'm pretty sure the 1x16 was/is the longest one made. Outside of the 1x? sized bricks, the longest plain shaped brick that I know of is part #30072 or #47122 at 24 studs long.  I don't know about other brands though.  

Interesting related post:
What is the largest single LEGO piece?