Andrew from Boston sent along the following. It kind of reminds me of the curiously strong bike light made from an Altoids tin posted on Instructables. If the hacker who came up with this reads this post, give us a shout out, we'd love to hear about the process.
Not my hack, but a few days ago I spotted a rear light setup where the batteries (I presume) were housed in a Tealuxe tea tin. The lights seemed to be an LED strip attached to the left seat stay. Spotted in Boston (more specifically, Porter Square, Cambridge, MA).