Is there any way we could implement a flattr button on artists' or manippers' pages, or on posts, so that artists could have a sort of "tip jar"?

It'd be nice if content-creators could be incentivized to create material for the new site, and I for one would be happy to put a bit of money in a flattr account regularly and have it be automatically split between the people I click the button for, each month.

I'm told it's really easy to implement, so maybe a feature request could be made... but I believe it might be as easy as adding a few tags to artists' profile pages, so we could probably do it ourselves pretty easily.

That would be a pretty cool idea, if it's at all possible to do. I know Vanndril's tried to do things as simple as change the CSS, and it's completely broken the site layout every time. We could possibly make a feature request, but I doubt the dev would make it a priority (at least I hope he wouldn't, because I'd rather him focus on fixing the critical bugs).

It's definitely something I'd be interested in doing. However, it's not as simple as it seems.
This site, like the old booru, is made dynamically via PHP script. In other words, the actual .html pages you open to view the pages of this site don't actually exist.

When you open a page, PHP scripts from various source files work together to compile the needed page. This page then renders in your browser. So, in order to add something like a flattr button, I'd need to understand all this PHP nonsense and how to include a custom PHP script in the collection of scripts that compile the artist profile page.

Quite plainly, it's not so simple.

The best we could do is suggest it to the developer in some way. Or to find a similar service that doesn't require HTML to add a button for.

This code open source?

Maybe I could just program it in for you.

You and offering to fix and add stuff. I like you. ^^
I linked to it in my reply to you in the forum bug announcement, if you want to go check that.