Capitol One offers savings accounts yielding 0.75% APY with no minimum deposit. I've used them for over 10 years with no hassles. Your general point about low yields still applies, though.

I would estimate an opportunity cost of 3 hours per year to set up the account, shuffle money around, periodically monitor the balance, and pay taxes on the interest. This opportunity cost will vary depending on how efficient one is with paperwork. Whether this is worthwhile depends on the size of the emergency fund and the alternative options for increasing marginal income via an equivalent time investment.