Venn diagrams are used for more than just useful stuff like science and demographics. Diagrams just for fun are still useful in that they make the concept of graphic sorting and labeling of relationships easy to understand and appreciate. A true Venn shows all possible overlaps between sets.

This one can be an introduction, but it's far too simplistic. There are plenty of diagrams that feature circles but are not Venn. Pie charts are the first that come to mind. Many images labeled as Venn diagrams are actually Euler diagrams, which show sets and overlaps, but do not have to show all *possible* overlaps, just *existing* overlaps. Some diagrams veer off into hard-to-label territory, but that's alright as long as we get a smile from them.

Jason Eppink bought the domain "senselessvenndiagrams.com" and uses it for many interesting pages, but his index page is the only one with a Venn diagram, using four ellipses. It's not senseless at all, as the overlapping fields categorize links to Eppink's creations and other sites.

The post 6 Animals that Show Mother Nature's Sense of Humor took a cockeyed look at crossing one animal with another to make something completely different. Many fantastic beasts from folklore follow this trend. Jim Unwin diagrammed various mythical creatures by the parts contributed to them by real animals. View the full-size version to see how the unicorn is the overlap of a horse and a narwhal. The circle in the middle is, of course, a human. This is an example of an Euler diagram.

This diagram from Despair.com slots your perfect social networking site(s)Â according to your personality disorders. The diagram is available on a t-shirt. I have accounts at all those places and more, so all my idiosyncrasies are covered.

It only makes sense that Vin Diesel should have his own diagram. The overlap is nothing to be proud of, but hey, do *you* have a diagram?

This timely chart tells you what to do for her on Valentines Day. The vertical axis is how much money you have, and the horizontal axis is how much you care for her. This one is a bubble chart instead of a diagram, but it has circles and may be useful for the upcoming holiday.

GraphJam has a generator anyone can use to create graphs on any subject. The potential partner diagram is obviously from someone a bit depressed about the mating game.

You'll find many diagrams more or less explaining songs at JamPhat and GraphJam. Making song diagrams is now a popular pastime and shows up in other places as well. This diagram of a Simon and Garfunkel song was seen on the TV show *How I Met Your Mother.*

Here's a Venn diagram that shows the intersection of two opposites. It doesn't sound logical, but these are human emotions, which are rarely logical. We've all held simultaneously happy and sad feelings, although the contents of the overlap are personal and will vary. The Happy/Sad diagram is available on a t-shirt.

Is this a Venn diagram? Jeffrey Rowland at the webcomic Overcompensating created a diagram about the trend toward comedic diagrams. A reader told him it wasn't a true Venn diagram and so he produced the diagram shown here. Then he was corrected again and told that the original was a true Venn.

VENN DIAGRAMS: NOBODY ACTUALLY UNDERSTANDS HOW THEY WORK EXACTLY

How true.

See also: Fun with Venn and Euler Diagrams and Fun with Pie Charts.