I finally gave up and got all squirrel proof feeders. I have had good luck with ones similar to this:
http://www.bestnest.com/bestnest/RTProduct.asp?SKU=HF-7536I also got a tube one this year enclosed in a metal cage that smaller birds can go in - however, this is my second one - the first one had plastic at the top that the squirrels chewed through. This year I got on that is metal at the top so they can not chew on the top.
http://www.bestnest.com/bestnest/RTProduct.asp?SKU=WDL-COPCAGE6Sis similar to what I have.
I also have a squirrel feeder, and throw seed on the ground for the birds that eat on the ground and squirrels. There will always be that one squirrel who somehow manages to hang by his feet and heat out of the feeder, but at least the food isn't getting spilled all over the ground like it was before.
I'd stick with metal feeders - wood and plastic will get chewed up. The squirrels even came into my screened porch through the doggie door when I didn't get food out quick enough - so I started storing it in the house - but that was a bad idea, cause I've now been dealing with a bad moth problem in the house. Now I keep it in a metal can on the porch. I buy something called squirrel munch mix - nuts, corn, sunflower seed - the birds like it too.
Meg