Hi John!
you could make a website with all your unofficial errata-work and ask for a voluntary donation through a Paypal-account. Though I do not know if this would be legal.
When 3.5 errata is concerned, I have only found this old thread in the Wizards-archives:
DO NOT PRUNE: The 3.5 (potential) Errata thread [Archive] - Wizards Community
You could also open a new 3.5 errata subforum on the Wizards-community website for your future projects.
cheers!