@MODS, don't worry. I'm only telling people about the fun things, but I'm not going to tell them how to do them. That'd cause chaos.
10: You can post in a thread after it's locked
As you can see with the last two posts, you can post in a thread after it's been locked. This one is well known about so it's at the top of the list. More just annoying than cool.
9: You can make people see a blue quote icon even in threads they've yet to post in
I can't show an example of this since it's only a per person thing, but eh it's cool.
8: You can make threads that don't exist
As you can see by the url, it looks valid. However clicking on the link will just give you errors. This thread exists in a sort of limbo. You can see it on the index pages and the like. Name is "error thread."
7: You can make threads without Titles
This one is just annoying because no one can click on the name to enter the thread.
6: You can make the \ symbol
Well you can't, but I can.
5: You can be a time traveler
The link says it all
4: You can put autoplaying music in your profile.
Mods decided that was bad so I don't have an example, sorry.
3: You can make threads anonymously
2: You can go to the underground
Some people know about section 8 (both those links are usually referred to as section 8), but what people don't know is that there are a lot more than just those 2. I dare not link to the hardcore ones. #banana
1: You can edit other member's posts
*You just have to be a mod hahhaha
No, you don't have to be a mod ;)