As I have to handwash many delicate items of clothing every week, this Take-Away Sink would be ideal for me. I could put the wastewater right into the toilet when done.

This is such a great idea, though I agree with Leanne about the drain. Another approach would be to ditch the stopper altogether and have some kind of sliding door on the bottom and maybe with some kind of interlocking mechanism make it close automatically when the sink is pulled off.

Needs to be worked on, so that the plug doesn't suddenly come out walking across the livingroom, so that someone doesn't turn the tap on full blast when sink is gone, etc, but it has wonderful possibilities. Use the dirty dishwater/hairwashing water to flush the toilet! Wash and peel your vegetables in the sink and then take it out to dump it in the compost!...

It looks very nice but I saw recently smth similar at http://www.inewidea.com/page/2 The difference is that this Hughie Sink (as they called it) fits existing kitchen sinks.