One thing folks can do that helps a lot is to have the guts of a post typed up well in advance of their turn in the order. Usually once the EC posts for the NPCs, the players at the event should be able to start formulating their PCs' next action immediately. If you're not first in the order, you have some leeway to prepare some descriptive text or whatever since you have a bonus five minutes to post.
This obviously doesn't always work - sometimes you need to activate your wonder twin powers with another PC, or another PC walks up and puts a bucket over the monster's head, thus leaving no way for PC #2 in line to punch said monster in the face; no one likes bucket punching. If you find that you're always dependent on someone else's actions, try to move to a spot in the order that gives you time to react. Knight goes two slots before the squire, etc.
Also, please bear in mind that a combat round might take an hour of wall clock time for a 10 person event, but it's about 10 seconds of time IC. It's good to consider that when you're describing your character's action!
One technique I've used that some people like and some absolutely despise is putting the burden of resolution on the storyteller. The storyteller poses for the NPCs, and then everyone sends their characters' actions to the storyteller all at the same time, and he or she resolves the round. You need to trust your storyteller, but it can have some perks. There's the element of surprise, it takes away the serial nature of A follows B follows C in a standard pose order, it lets character interactions happen in some unexpected (but usually fun) ways.
