We just happened to have some empty water jugs (not a usual staple at our house) sitting in our to-be-recycled bin and a bag of unopened bird feed in our school closet, so we had an impromptu bird feeder making session during one of our snow days.
And the important part is that they work, too! We had birds within 5 hours of hanging them!!! The feed we have in there seems to really attract cardinals! The boys and I really enjoy looking out the front windows and watching them.