Sometimes I see conference organizers say "well, we didn't have a choice about the talk proposals we got!" or "we just picked the best ones!". I think we all know by now that that's bullshit, but just in case -- it's bullshit! =D
We have a choice about who submits talk proposals, and also about who submits the best talk proposals. I watched somebody I know get talk proposal feedback today, and their proposal started out good and got dramatically better. Now it's great.
If you ask someone specifically to consider speaking at your conference, they're WAY more likely to consider submitting a talk than if you don't. If you then actively work with some talk submitters to help them focus and improve the talk they submit, their proposals will get better! And if you choose to focus your energies to work with (for instance) non-white people more than white people, then you'll get more and better proposals from people who aren't white.
You can see this with PyCon! 30% of the talks at last year's PyCon were women, because lots of people have done tons of individual outreach to encourage their friends to give talks and spent lots of time working with them to write good proposals. As Jessica McKellar says:
Hello from your @PyCon Diversity Outreach Chair. % PyCon talks by women: (2011: 1%), (2012: 7%), (2013: 15%), (2014: 33%). Outreach works.
This makes me really happy! It means that if I'm working on a conference (like !!Con), then I know I can help get more diverse participation by sending emails to individual people who I'd like to hear from. Telling people that I like their work and that I'd like for them to talk about it is super fun! (and true!)
If there's something you find exciting about programming and you often find you're part of an underrepresented group when you go to conferences, I'd love it if you submitted a talk to !!Con. Double especially if you live in NYC!