Yep. And Twitter's a decent way to make first contact, but there's nothing quite like f2f meeting. Also, be friendly to lots of people. You never know when one of them can introduce you to the right person or invite you to the right dinner where your target might be.

Also, nice little hack if you want to go but can't afford it. Volunteer at the conference! Most of these things need a lot of staff and as a bonus, you'll often get to interact with the people you wanted to target backstage and so on. It's really not that different than open source work, though obviously, it helps the people putting on the conference. But honestly, I don't see them as middle men. They take a lot of risk and many of these conferences lose money. It's an entrepreneurial endeavor that requires a lot of blood, sweat and tears. They're far from rent-seeking in my mind.

Particularly dev conferences, there's a lot of good connections and things you can learn, and the people running it have good motivations to help the community. I would really try to be more empathetic toward them.