Jump from a height great enough to cause fall damage, hold +use and land on a PG = no fall damage.

e.g. on ns_lost,

-place a PG next to the RT at the equi hive
-climb up the ladder
-jump straight down (aiming for the PG below you) whilst holding +use
-you will teleport to the other gate, with the same health.

Well this makes sense, since you are never hitting the ground. Is it intentional? Probably not, but its also not that big of a deal.