what is solderless post
Are you talking about male and female header pins? They "mate" with each other to form a decent connection but you still have to solder one end of them down. Very useful for prototyping though as once you have soldered in the one end, the other end basically makes a breadboard.

Or perhaps POGO pins would better suit your needs. They are generally used for flashing/testing a part that is going into production when you don't want to leave the connector on. The basic idea for using pogo pins is you create a secondary board with pogo receptacles. They allow for good temporary connections without any additional hardware on the primary board. See the sparkfun tutorial. That is what they use for their quality testing.

Lastly, wire wrap is a good way to make an electrical connection without the need for soldering.