[mindcrime]

My understanding is that whether or not endorsement is required is dependent on which "area" you submit to. And even if I'm wrong about that, "endorsement" in their terms is really just meant to mean "this person is not a total quack / spammer / etc." So don't feel shy about reaching out to people in the academic community who are potential endorsers and just ask "I want to submit this to ArXiv, would you be willing to give it a quick look and possibly endorse me so I can submit?"

If you already know somebody in the academic community, it would probably be better to try them first. But if not, it appears that ArXiv etiquette allows cold-emailing people... they just ask you not to blast requests out to mass numbers of people simultaneously.