What you need:
(that's what I used at least. Corel and Inkscape would probably be fine too...)
1/4" birch plywood
cut to 24" width by 12" high. I cut it on the table saw with help from Kyle. Thanks Kyle!
Epilogue laser cutting machine
(or dropbox would work fine)
Note: the laser cutting machine will hold a board up to 24"x18". I cut mine arbitrarily and didn't use the whole piece.
To make the mobile part:
This is the tutorial
I am using to make the actual mobile part. You could laser the hoop or just use one from a sewing store.