I have recently bought an iPad. On my PC I use Feeddemon to aggregate RSS feeds on my industry and use the "watch" function to search all those feeds automatically for key words relevant to my work (a watch is effectively a saved search that runs automatically). You can have one watch for multiple keywords (e.g. "soybeans", "wheat" and "corn" are all in the same "agriculture" watch).
This seems an obvious thing for any business user to want but I can't find an iPad RSS reader with an equivalent function. Does anybody know of one?