Lint balls from navels (navel fluff, belly button fluff) won an Ig Nobel Prize in 2002 for Karl Kruszelnicki. Dr. Kruszelnicki worked on observations reported in a survey of 4799 lint-collecting people, rather than on tons (I use that word here metaphorically) of individual balls from a single person.

I am a forensic investigator, with a new (to me, I mean) interest in lint. I mentioned this during a radio program. A few weeks later, a young couple (Elisabeth and Jan from Dresden) approached me after a public lecture and handed me a full collection of lint balls collected exclusively from their own navels. This allowed me to examine 167 lint balls from two persons instead of many different lint balls from a large number of people.