Bad birds, bad birds, what ya gonna do…

I’ve had a flock of grackles hanging around my feeders for 3 weeks now, sometimes 50 birds at once. Usually the grackles move on after a week or so but these seem determined to stay. Perhaps I need to make the yard less attractive. Four regularly filled seed feeders, suet and three bird baths may be too hospitable.
I always provide food for whatever birds show up and that has worked fine, until now. The grackles are too aggressive and they bring lots of friends. The little birds are getting knocked off the feeders and scared away until the grackles are finished. And they eat and eat and eat until nothing is left for anyone else. They can consume a suet cake in one day. The only bird that doesn’t back down to them is the Blue Jay. I had a Cooper’s Hawk show up and that chased them away for a few days but alas, they returned.
I’m considering replacing one of my feeders with the type that has the wire mesh around it so only the little birds can get in. At least the little guys will be able to eat. Also, I hear the upside down suet feeders are an option that woodpeckers, chickadees and nuthatches can use but not the big birds, so I can add one of those.
Anyone have a better suggestion? I’ve gone through 50 pounds of bird seed and several suet cakes a week this month.
Update 10/13/2010:
I replaced the sunflower seed in the white tube feeder with safflower and I stopped filling the tray feeder with cracked corn, nuts and millet and instead left it empty. I also left the suet holder empty. Within a week the grackles were almost gone except for one or two. The number of sparrows also declined but the number of cardinals and finches doubled.
Last weekend I put the suet back up and put seed and nuts back in the tray feeder. I’m leaving the safflower out as the finches, cardinals and chickadees are eating it. So far so good.