Methods for batch populating PCBs without a pick and place
Avoid through hole parts. Don't put components on both sides of the PCB.

Apply solder paste with a stencil, arrange components, bake/reflow.

(update)
Here's a great video series from a guy who built 100 little dev boards in 10 days.
http://fletchtronics.net/blog/100-bumble-bs-10-days