LimeWire for many years was dead-set against this concept. Then promptly introduced something similar in their later version 4 versions. However I 'suspect' the LW re-search is based on the ip's at the time it was initially downloaded. Which doesn't work with dynamic ip's of course. I don't think the LW re-search is keyword based. Likewise I think the LW one is based on every 30 minutes or so.