Depending on the school of economics you subscribe to, there should never be a surplus of people. I mean, just go outside and have a look at the streets: if you don't live in Singapore, there's plenty of work to do even just cleaning them up. We could pay people to do that.
Ah the Keynesian solution of paying half the unemployed to dig ditches and then pay the other half to fill them up.
That kind of "employment" already exists - known as 'social work'.
You could let them actually do some useful work, too.