A rather serious site dedicated to lowercase L sightings and the psychology thereof:
The purpose of this blog is to to provide a forum for people to submit their photos of lowercase L sightings, and to discuss the psychology of the lowercase L offender. And if you are one of those people guilty of writing all-caps signs with lowercase L’s, we welcome and look forward to understanding your unique perspective in this matter.
[W]hen people create handwritten signs, they sometimes choose to capitalize every letter except the letter “L”. …. [H]aving lived in NYC for ten years, I have seen the lowercase L rubbing shoulders with uppercase company more often than you might imagine. So often, in fact, that I wanted to bring the case of the lowercase L to the attention of the public.
Start spotting: the criteria for a good lowercase L sighting.