Venn diagrams give a visual representation of sets and their logical relations and overlaps. The actual logic behind these nine diagrams varies according to the humor intended.

1. Animals Playing Music

This Venn diagram explains how such diagrams work with no words at all. It's a t-shirt from Tenso Graphics called Math, also available as a poster.

2. Muppet Names

There is a method to the madness of naming the Muppets. You could probably stick a few more of them in here if there were room.

3. Dating Expectations

This diagram illustrates how both men and women have expectations of meeting the opposite sex in more diverse places than they actually do. What's that bar at the bottom? Oh, that's a progress bar... when men and women finally meet at a bar. See this diagram in motion at Top Cultured.

4. The Origin

What does it mean when alcohol overlaps Japanese culture? The invention of a new pastime!

5. Van Diagram

Adam Koford designed the Van Diagram t-shirt for Woot! You are warned not to wear it backwards because people will think it says "boxcar" and that doesn't make any sense.

6. Shakespeare in a Minute

Several diagrams illustrate some of Shakespeare's most enduring lines from various plays. Only those somewhat familiar with the Bard's works will find this entertaining.

7. Nerds and Geeks

Are you a geek or a nerd? How you answer that question (one or the other, or a long rant about the definitions of the two terms) determines where you fall on this diagram by Randall Munroe of xkcd. If you are neither a nerd nor a geek, your opinion on the distinction is mild compared to those who have a stake in the controversy.

8. Real World Tables

These nesting Venn-inspired tables (there are two of them) can be reconfigured as you like so you can illustrate overlapping sets to people who visit your home. Whether they ever return again will depend on how math-savvy and tolerant they are.

9. The Last Word

There are generators in which you can enter specific data to create your own Venn diagrams. Here's one I have used before. It's much easier if you just make up your data out of whole cloth; I made this simple diagram myself with a paint program.

See also: Fun with Venn and Euler Diagrams and 10 Venn and Not-quite-Venn Diagrams.