SASS: Storing `&` in variable

Apparently in SASS you can store the current selector in a variable, eg a{ $a: &; }. Useful for dealing with some limitations of & without having to repeat selectors.

I've run into the example that Jake Wilson did, where something like:

.foo{
	&Bar{
		color: blue;
		&:hover .fooBiz{
			color: red;
		}
	}
}

could by DRYer as something like:

.foo{
	$l1: &;
	&Bar{
		color: blue;
		&:hover #{$l1}Biz{
			color: red;
		}
	}
}

I could also see it being used for the trick of duplicating selectors to increase specificy, eg:

.foo{
	$l1: &;
	&#{$l1}{
		color: red;
	}
}

Neat.