I play 2v2 games on ladder. I am Terran and my friend is Zerg. Currently we use generic 1v1 build orders, but from my time as Warcraft 3 2v2 player I know there were certain tactics that benefited the team by trading resources at specific timings.
A very common tactic with Undead and Nightelf was to go Fiends and Huntresses. The Undead gives the Nightelf player about 40-60 Wood as soon as he starts his Altar. This way he gathers just enough wood to create the Ziggurat on time (without delay), as Gold was the limiting factor, and the Huntress Hall gets created a bit faster (about 10 seconds) which is a huge deal. Afterwards the wood gets swaped back, so the Undead player could tech on time.
My question is: Is there some strategy for Terran and Zerg that also benefits from such resource trades in Starcraft 2?