This year I spoke at HOPE - Hackers On Planet Earth. The topic was "Hacking ATMs: past and present". I really enjoyed it, it took a lot to prepare though. I haven't gotten any monetary benefit from it, but I would definitely do it again.

HOPE is one of the best hacker conferences, and it's somehow [subjectively] friendlier than other. Feels like home, so if you're on hacker news, I guess you wanna speak at hacker conference or contribute to 2600? ^_^