This container has overflow: hidden; applied to it, and it "haslayout". This container contains it's floats in all browsers.
This container does NOT have overflow: hidden; applied to it, but it "haslayout". View this in IE to see that this container does indeed contain it's floats.
This container has the class of clearfix applied to it. This container contains it's floats in all browsers.
This container has an extra div thrown in below it with the class of clear. This container contains it's floats in all browsers.
This container is floated also. Therefore, this container contains it's floats in all browsers.
This container simply has display: inline-block; applied to it. This container contains it's floats in all browsers.
This container has display: table; applied to it, and it "haslayout". This container contains it's floats in all browsers.
This container has position: absolute; applied to it. This container contains it's floats in all browsers.