Public Speaking: Where can I find someone to represent me as a speaker?
My answer to Public Speaking: Where can I find someone to represent me as a speaker? on Quora
There are speaker agencies that specialise in this kind of thing, but they’re mainly targeted at larger events which expect to pay $5,000-$50,000 or even higher for speaker. They might not be as well suited to setting you up with gigs at startup events, which are less likely to pay enough money to make it worthwhile for an agent (most agents take a cut of the speaker fee).
Have you considered hiring a virtual assistant to help you track down events to potentially speak at?