There have been several threads on this before, and there's a lot of good advice earlier in this thread to.
One thing that really helps is to have at least one PHB per two players, plus one Spell Compendium (and other heavily-used spellbooks) per two casters, at the table. Plus, the DM should have a dedicated copy of any and all rulebooks he's likely to need, which the players are forbidden to reference.
Try to eliminate the need for the DM to look up rules, especially in combat. If you know your Wizard is going to cast Disjunction, look the spell up in advance, and hand the PHB to the DM at the same time as you declare the action. That way, if he decides he needs to reference the rules, they're already to hand. If he doesn't, you've not really lost anything. (Likewise, Fighters using Grapple, Monks using Quivering Palm, and so forth.)
In general, remember that the most intensive part of D&D is the combat sequence, and during a combat the DM is 'on' 100% of the time, while each player is only 'on' 20% of the time (in a 'standard' 4-PC party). This gives each player 80% of the round in which to do various things to speed the game for the whole. So, use that time.
I would echo the advantages of cheat sheets, spell cards, and an initiative caller. But the #1 piece of advice I've seen so far in this thread is for players: pay attention!