More to explore:
Path Sign Up
Path Login by Adrien Rochet
Dribbble - Sign in to website by Gevi Marotz
Nice subtle pattern in the background.
Lkd.to Landing Page
EyeEm Android sign up flows screenshot
We could potentially do a slider that switches the input boxes from "user" to "organization". With some sort of nice transition, without leaving the page.
Light vs Dark by Josh Austin
30 Examples of Sign-Up Web Forms for Design Inspiration