In Reply to: Well, that's what I thought except it posted by Balimagic on Thursday, 18. May 2006 at 09:13 Bali Time:
It would keep weight down in the sense that you could use a smaller bag, or less bags in total. Bags can often weigh more than you realise - especially suitcase type bags (mine's not huge and weighs around 7kg empty).
They won't, however, reduce the weight of the contents of the bags.