Homemade Birdfeed and my Squirrel Problem

I spend quite a bit of time at my kitchen sink catering to the needs of my household.  Luckily, my kitchen sink is directly under a large window that looks out into our side yard, which is filled with lots of trees and nature that helps me forget I'm doing dishes.  Several months ago I put up a great bird feeder so I could look at some exciting bird action while I wash away.  There were a few issues with the whole set-up, but problems are now solved and it works like a charm.  Cardinals, blue-birds and many others show up to feast, and I love it! 

The birds have come in swarms, and so my food was running out pretty quickly.  Then, the other morning, I looked out my window and a damn squirrel was sitting at the top eating away!!  I couldn't believe it!  I thought these were not supposed to be easy for them to climb!  Then, the next morning we saw that he told his friend and they were both hanging around, but left when I went out to try to snap a picture of them.  So, I'm currently trying to figure out how to stop the squirrels.  

In the meantime, though, since it seems we will be going through lots of bird food, I decided to make my own since it's pretty expensive at the store.  I did a little reading online and here's what I came up with - so easy and MUCH cheaper than store bought bird feed:

Generic cheerios (can be crushed a little - I crushed some with my hand)
Shelled Peanuts (chopped them in food processor)
Shelled sunflower seeds
Dry oatmeal
Dry corn kernels (bag of popping corn)
Raisins

I've got some of the cheerios and oatmeal left over for next time, and will try to buy some of the other things in larger quantities next time.  I used one jar each of the peanuts and sunflower seeds, one large bag of corn, and some 
I put it all together in a huge bowl and WAH-LAH!  Cheap bird food!