I sometimes think that search tools are like my local bus: none comes along for ages and then three turn up in quick succession. For quite some time Beagle and Kat have been meeting the needs of users like you and me who fill up their hard drives with the results of our internet meanderings and because we have been remiss in keeping those drives well organized we eventually have to use search tools to find that PDF or HTML article we spent an eternity looking for.