If you have a talk proposal that's a bit more technology-agnostic, and/or you want a bit of a niche audience, submit to the bigger conferences in the different languages (your PyCons, RailsConfs). I think you'd have a better chance of being accepted that way.
For example, I didn't bother submitting my “How to be a Better Junior Developer” talk proposal to RubyConf, since there's probably a lot of overlap between attendees there and RailsConf, both being in Chicago and in the Ruby/Rails world.
Don't put pressure yourself to come up with a totally original idea, or on a technical topic, if those aren't the ideas you have right now. I've found a lot of other programmers that are also very interested in the intricacies of communication and psychology. Also, it turns out that the beauty of giving a talk on communication is that the people that come up to you afterwards are pretty much all into the topic. Because after all, the people who disdain the topic are probably not great communicators themselves, and poor communicators don't communicate :)
I think in a way, it might be slightly easier to get a talk accepted at a big conference, since there's a wider variety of interests in the attendees. The small regional conference feels a lot more manageable though, and an unforeseen benefit to me is that if you speak there, you become more known to the more prominent members of the community that are also speaking there since they're sitting through all the talks at the conference.
