I am aware that this has been done before. Lots. But, it's fun to write and I have a few ideas so I'm going to give it a go anyway. I have no idea how long this will go on for or how often it will be updated but it will eventually be a collection of one one-shots about the marauders & friends passing notes.
In this fanfic, imagine that, when I say enchanted parchment, they're writing with special parchment. It's kind of like James & Sirius' mirrors I guess. You write your message and whoever your message is for, provided they have a special parchment can read it. This just seems like an easier way to have conversations including lots of people and, considering who this is about, doesn't seem particularly far-fetched.
To avoid confusion, when there are a lot of characters talking, because there are only so many different combinations of bold and italics and that can get confusing anyway, I have just put their initials after what they are saying so you can tell who's saying it.
And now, after that ridiculously long author's note, the story:
Divination via Enchanted Parchment
I'm so BORED! - SB
Well, if you paid more attention, you wouldn't be so bored - RL
Yes I would, it's Divination! - SB
He has a point Moony - JP
Could you stop? I'm trying to concentrate! - RL
Yeah, Padfoot! If you distract him, he won't be able to give us his notes! - JP
Just stop. - RL
What are you gonna do about it? Give us detention, Mr Prefect? - SB
I hate you both - RL
Someone's grouchy - SB
Well, apparently my friends only talk to me so I give them my notes from class. - RL
Oh no! Who would do such a thing Moony?! :O - JP
Beats me. - SB
On a more serious note Moony, we don't just like you for the notes - you're also a great help with homework! ;-) - JP
Moony? - JP
Oi! Moony! - JP
Hey! REMUS LUPIN! Stop paying attention to the lesson right this instant and pay attention to us! - SB
I thought you wanted me to listen so you don't have to? - RL
Well, I changed my mind. I'm bored. Let's do something. - SB
I'm almost afraid to ask... - RL
You're no fun anymore Moony! - SB
Yes I am, I would just prefer not to fail this class... - RL
Urrrgh! Who cares? Like I said before, it's Divination! - SB
Fine. What do you want? - RL
Yay! Let's plan a prank on the Slytherins! - SB
Ooh! Good idea! - JP
What should we do? - JP
History of magic - normal note passing
That was a nasty prank you pulled on poor Sev earlier. - LE
Come on Lils, he was asking for it! - JP
That's beside the point! It was a horrible thing to do. - LE
But he's a Slytherin! - PP
I hardly see how that justifies it. - LE
Oh, come off it Evans, stop pretending like you're friends! - SB
He was my best friend. - LE
Yeah, until he showed his true colours and you saw him for the slimy git that he is. Trust me Evans, it's no bad thing that you don't talk anymore. - SB
Well, so what if we're not friends? That still doesn't give you the right to be so awful to him! - LE
He gives as good as he gets. - RL
Damn right he does! - SB
Remus, I thought you were better than this! You're supposed to be the most sensible of the marauders! - LE
He is! - JP
Well...the bar isn't exactly high... - RL
Touché - LE
Yeah, being less sensible than us would be a huge achievement! I have yet to meet someone who even comes close. - SB
I think we get it Padfoot. - RL
Hey! How come he's 'Remus'? - JP
Wait a minute... You're right! I am insulted, Evans! - SB
Um...that's his name? Or would you prefer I used those ridiculous nicknames you have for each other? - LE
No, I meant, why is he 'Remus' but we're 'Potter' and 'Black'!? It's quite hurtful! - JP
Well, Remus is my friend. It's weird to call your friends by their surnames. - LE
Are we not friends Evans!? - JP
No. - LE
Why ever not!? - SB
Remus is the only one out of all of you that I actually like. - LE
You don't like me? - PP
Really Wormy? You've not spoken more than two words to each other in the entire time you've known one another. - JP
But what's not to like about me? I'm good looking and smart and charismatic and- - SB
Modest? - RL
...So do you see why I don't like you? - LE
Not really. Sirius, I completely understand, but me? I'm- - JP
Almost as bad as he is. - LE
I AM NOT! - JP
You are - RL
But you do like Remus? - JP
Yes. - LE
Thanks Lily! :-) - RL
How can you like him but not us!? - SB
Thanks a lot Pads. :-\ - RL
No prob mate. - SB
It makes sense if you think about it...they're both know-it-alls - PP
Shut up Wormtail. - RL
And I think the word you were looking for was intelligent. - LE
No, that would be me - SB
No, a word to describe you is 'cocky bastard' - LE
Technically that was two words... - SB
... - LE
And you wonder why she doesn't like you... - RL
Oi! - SB
Also, can we talk about how we are currently passing notes in class with none other than the queen of all goody-two-shoes' Miss Lily Evans? - JP
Oh, come off it Potter, it's not like I've never broken any rules. - LE
News to me. - SB
Just because I don't make it a competition to see how many rules I can break like you guys… - LE
Oh yeah, I remember that. That was amazing. - SB
Besides, it's History of Magic, I think we're fine. - LE