As you know, I've happened upon an entire case of empty tennis ball cans. They somehow inspired me.
Here's how to make a BIRD FEEDER out of one:
Find a few sticks the yard and cut them an inch or two wider than the width of the canister.
Drill 4 holes through the tennis ball can, directly across from one another in order to slide the sticks through. You may need to play around with the diameter of the drill bit, it should be slightly larger than the sticks you are using.
I ended up using a sharp knife to remove the plastic that remained after using the drill.
Also drill a few smaller holes: one each over the stick perches for the finch food dispenser, and 2 across from each other near the lid to slide a piece of twine through to hang it.
Dab around each stick with some hot glue to seal the stick into place.
Fill with finch food and snap the lid back on!
The birds have found it already!