My guess is that you'd want to exclude the HN crowd and look for somewhere that's not exploited. We're all pretty good at navel gazing here and might well have thought of it.
I've always thought, for example, that secretaries/PAs are an underserviced market. They have jobs that involve a lot of moving parts (managing people's email, time, travel, special events, ...). I bet there's a start-up in there making them a service that they need.
