So.. I pick protoss. He is Terran. I see him NOT walling off, (Luna style, anyone remember this map? Hopefully one is made similar in sc2 so terran can stop playing like pussies),
I went something like 9pylon,10gate,12gas,14core,15pylon, the 'standard' response to a wall-less Terran PvT in BW. Instead of getting range and poking at his marines/scout/workers with a goon and a probe while going for a Robo or an expand, it's now... 'stalkers', which-to be honest- are just FIXED dragoons, and warp gate technology.
Oh and multiple building selection was a trip...
EDIT: Oh and before I found out about stalkers and warp gates, I would just drop gateways in 2's when I would reach 300 minerals so that both gates can finish at the same time and then I save up chrono boost and CB both gateways for a 2/3gate zeal rush.
Build order is something like 8pylon,10gate-10gate, 11pylon, 12gate. Worked against every single race, the first zealots go into a protoss base going 'standard' 9pylon, 13gate, 14gas, 15core, 16/17pylon right around when their core is being warped in, usually means insta-win for me unless the protoss went for a 10/10 gate rush too(happened like twice).
Terrans who wall-off know this kind of shit is gonna happen, so usually I rush stalkers instead of zeals, zerg tend to go for an early expansion and just making one pylon outside your main instantly sends that message to the zerg player that "oh he's going to fast expand, well me too!"
then I drop 10/10 gates and zeal rush.