https://gratipay.com/ exists already, and it's mostly (all?) open-source as well.
edit: finally got through their registration. You get: "Which category fits what you make best?"
Video & Film
Music
Writing
Comics
Drawing & Painting
Animation
Podcasts
Games
Photography
Comedy
Science
Education
Crafts & DIY
Dance & Theater
.. it's clear that programmers (unless you're a game programmer) are not welcome.
it's pretty impossible to have an exhaustive list of all the kinds of things you can create.. so we've been talking about ways to let people put in their own categories for a while now, but that also has its own set of UX complications.
$Manager: What are you working on today?
$Programmer: The usual Cratfting/DIY.
$Manager: OK, sounds good.