I have had this idea for absolutely ages now and according to ukrm you are just the person to ask if it will work. I like all sorts of tomatoes me but I like home-grown most of all and every other year I grow me own and am always up for a little trick or three to lengthen the growing season. One of the tricks is to grow the so called "patio" varieties indoors in a pot. Now this works well where you have a conservatory or something with glass to the ground and also the space to elevate them so that they can trail all on their own, which they do love but it is not a lot of cop on the windowsill. Tomatoes in pots on windowsills slightly out of their natural season are invariably not happy bunnies in my experience. So, I have come up with this idea. See, these patio varieties are trailing plants and are quite happy to dangle so it sort of occurred to me that it might be possible to grow them at the top of the window and let them hang down to flower and fruit. It needs a grow bag in a hammock really, what do you reckon?