Thanks for all the advice! Another friend of mine clued me in to the fake wedding band idea, so I'll definitely give it a go.
I don't really feel comfortable carrying pepper spray or knives.
Both times I *was* listening to music with earbuds, so I am thinking I need to get some of those huge, imposing headphones to re-enforce the "don't disturb" message.
And I like the Mormon idea, though I'd have to study up a bit on their beliefs so as to be more convincing.
And I'll just have to be more assertive and rude to people, I guess. The more bad experiences I've built up, the more I'll be able to cut the conversation short, I think.
I swear these guys have a sensor for people that are sad and lonely and take advantage of that. :/
Anyway, thanks for the advice! I will check back in if I get the chance to put any of it to good use.