A website for US-based temps, "physical delivery" of employees, is interesting. I'm not aware of any service that does this. Like Uber for people!
If physical presence isn't required, Elance, Odesk and even Amazon Mechanical Turk exist. Drives cost of labor down to the $1/hour range (globally competitive) - probably not what Sam is getting at here.
It's also really interesting to see this idea. My initial read is that this sounds like a response to the common criticism that Silicon Valley destroys jobs in aggregate ("software eats the world.") Will be fascinating to see if something emerges here.