What exactly is a crackpot theory?

I'll define a crackpot theory as:

1. An idea which makes you say, "Well that explains it."
2. An idea with a complete lack of testable evidence. Or, in other words, it doesn't really have a leg up on a completely different crackpot theory that explains it just as well.

Both this blog and humanity are all about crackpot theories.

Now go read my band's blog.