I was going to try to answer your question, but in my research, I realized I couldn’t really answer your question. It seems like the main hoplite formation was the phalanx. I take this from Hellas: Hoplites:

Do you know of some separate formation proper to the hoplite that was also widely used by them? I didn't see anything like that.

Phalanx formations, which were comprised of "blocks" of soldiers in close proximity (with shields to protect up fronts and spears of the first few lines protruding otu the front), seem to have been based on the strategic notion that massive force in a concentrated area could roll over the enemy. That, it did do. While reading up on the phalanx, it occurred to me that the British used a similar philosophy in its successful use of the "Square" through the 19th or early 20th Centuries.

Can anyone explain the difference between hoplite and phalanx infantry formations? ?Of what importance were these innovations to warfare during the ancient world?

The two words have quire different meanings. The Hoplite takes his name from his large circular shield and as such can be compared with such troop types as Fusilier, Grenadier, Lancer, Rifleman or Cuirassier.The Phalanx by contrast is a deep formation of men and is thus similar to the Napoleonic Column of Attack, or the formations adopted by Scottish, German, Swiss and Flemish Pikemen during the late Medieval/ early Rennaissance eras.The Greek Hoplite was trained in an offensive role; to rapidly close with the enemy and defeat him in close combat.? As such emphasis was placed on individual combat skills, strength and stamina. By the time of Alexander (although Greek Hoplites were still around during the early conquest of Egypt and Persia) the Macedonians had largely converted to a longer 16 foot Sarissa (Pike) which natuarally requiring two hands making the use of a Hoplite shield impracticable. Tactics Changed to a rapid advance by the 16 rank deep Pike Phalanx (presumably in open order) and when contact was made with the foe the rear 8 ranks advanced into the gaps in the files creating a bristling wall of spearpoints into which the enemy would be impaled by their own following ranks. Alexander's light troops and cavalry would then sweep in? from the flanks rolling up the enemy's line (typical Hammer and Anvil Tactics).The Romans took this one stage further deploying their Legions in three lines (each 6 ranks deep). Roman tactics differed from the Hellenistic in being largely defensive on the Battlefield. THe first line would employ missile weapons to break up the enemy's charge and then the second line would advance into the gaps between the files of the first to create a shield wall for pushing back the dispirited foe. The third line being held as a reserve to exploit success or form a bastion in defeat. Again auxillary troops on the flanks were meant to sweep in and roll up the enemy's line (The Carthaginaians under Hannibal beat this by attacking and defeating the auxilliarys before sweeping around the Romans own flanks and rear (as at Cannae).

I know this an old thread but I had to jump in and clear this one up.

This is incorrect.  A Hoplite is the name for a Greek infantryman of the classical age.  There is and was no such thing as a Hoplite formation.  An infantryman is called a Hoplite because of his equipment not the formation he uses.A Phalanx is the formation in which Hoplites typically engeged in battle.  It consisted of a square formation with a front as big as the commander could get it and the terrain would accomodate while maintaining a minimum depth of anywhere from 3-8 ranks.  Although it was not uncommon for a Phalanx to be even deeper, as deep as 50 ranks is reported in some ancient sources, 3-8 was typical.  Hobilar has it right in that the German Landsknechts and Swiss Pikemen of the 15th Century used a Phalanx as their battlefield formation.The Romans used a modified phalanx that was not a solid mass.  Instead, the Romans broke their formation down into 40 man Maniples that essentially formed a Phalanx of Phalanxes.  When seen from above a Roman formation would have looked like a checkerboard with the black squares being maniples and the white squares being the spaces between the manipular Phalanxes.

Kelly DeVries wrote an excellent study of Phalangeal warfare called The Western Way of War in which he dissects Greek Hoplite warfare.  If this is an area that interests you it is well worth reading.  The lopsided casualties mostly resulted from fleeing men being cut down.  It is much easier to stab a man in the back when he is running away you know?