A real world example of a diffrent topology is is a dress whose straps intercect with one wrapping around the other so they from an X on someones back.
http://www.zadehome.com/images/product/Racerback_Nightie_2_M...
But I think that falls into the category of "sack with a couple more holes".
I can't find a picture of it. However while this is still a "sack with a couple more holes" http://s7.kmart.com/is/image/Sears/049B018579550001?hei=500&... if you picture having that strap be wrapped around at the point of intersection it can still be unwound. However, if you form a slip knot at the intersection it can not be removed by deforming the garment.