Flat footed and initiative order

3.5 Edition Rules:

Catching your opponent flat-footed is an advantage of high initiatives that is easy to overlook.  From page 137 of the Player's Handbook:  “At the start of a battle, before you have had a chance to act (specifically before your first regular turn in the initiative order), you are flat-footed.”

This gives characters the same bonus they would get when surprising an enemy.  This is especially valuable to rogues because it can allow them to apply sneak-attack damage to their attacks.