Box designer: http://boxdesigner.connectionlab.org/
Hollow project enclosure: http://makezine.com/projects/hollow-2×4-project-enclosure/
Examples from Aaron:
- simple laser cut: https://www.flickr.com/photos/asherwood/sets/72157632978189872/with/8551085926/
- cnc, 3d print: https://www.flickr.com/photos/asherwood/albums/72157635002757399
- large: https://www.flickr.com/photos/asherwood/albums/72157638857575213
Makezine examples: http://makezine.com/slideshow/15-fantastic-project-enclosures/