The BZL is a spin-off of the Avengers Message Board. Baron Zemo graciously created it when the AMB was getting over-run with parodies, so now the 'Parodyverse' is based there instead of here.
Just about everyone who posts to an internet messageboard uses an alias. Over at the BZL, these on-line names are turned into full fledged alter-egos. People write and post stories (usually less-than-serious ones) using their fellow posters as characters. It takes the 'escapist' element of comics to the next level: Instead of reading a comic and imagining that you are, say... Captian America, YOU (well, your alias, really...) gets to have the adventures for you to read about. The more stories that you contribute, the more 'interactive' the whole thing gets. That sounds a bit more calculated than it actually is... In reality, most people go there to have some fun and make each other laugh.
The stories themselves take on all forms. The occasional serious ones slip through, but for the most part, people try to keep the tone pretty light. Some are massive, multi-part epics, some are short, self-contained vignettes. Some are about world domination, some are about bowling, and some are about romances on sinking ocean liners. What do any of them have to do with the Avengers? Not much, but then again, maybe a lot. (It's no coincidence that, following Moses Magnum's appearance in the pages of Avengers, Mr. T began terrorizing the people of the Parodyverse.) Since most of the posters at the BZL came from the AMB, parodies about comic-book storylines (as well as comic book creators) are common, but movies, television, and politics have all shown up as well.
Admittedly, when you first visit, you may have trouble following what's
going on. It's kind of like starting to read a new comic right in the middle
of some on-going storyline. There is a certain continuity to the
Parodyverse. The solution? Ask questions. I don't recall ever seeing
a question go unanswered. Ultimately, my advice is to imagine you just
moved to a new town filled with insane people, like in 'Northern Exposure'
or 'Newhart'. Eventually, your neighbors will seem to make more sense.
Hopefully.
So how does one join? Simple: post there. The more you post, the more likely you are to start showing up in people's stories. You don't have to write any parodies yourself, at least not right away. Simply reading and replying to other people's work will get you noticed. An introduction is helpful for those who really want to get a part in a parody. The more people know about your character, the easier it is for them to write about him/her. Write a 'bio' descibing yourself/character. Feel free to give yourself super-powers, a speech impediment, whatever.
Eventually, you'll probably end up writing a story yourself. Don't worry about it. While we have some professional writers at the board, we don't deal in a lot of criticism. Everyone realizes that nobody's getting paid for the work they post there: they're doing it solely to entertain the rest of us. As a result, we're a pretty appreciative audience. The worst thing that is likely to happen is that you get hounded to write some more. Besides, IMO, the best way to start showing up in Parodyverse stories is to write 'em yourself.
Well, I hope that gives you some idea what people are up to over there.
-Visionary