Log Bird Feeder - 23 DIY Birdfeeders That Will Fill Your Garden With Birds (my note: I haven't looked at all of these, but at least one is a terrible idea. The window birdfeeder -- birds could fly into the glass and hurt themselves.
Sparrow Nest Box From Old Boots And Pallets ~ Build this sparrow nest box out of old boots and pallet wood. An easy to make, simple nest box that’s made from free materials. With Step-by-Step Instructions.