Line drills:

Two lines face each other, the player at the head of one line has the ball. The first two players in each line run towards each other and the player with the ball passes to the other. When the ball is received, the next player in the first line comes out and the ball is passed again. After each player's turn is finished, they run to the end of the line to which they threw.

Variations:

Add defense. After a player passes the ball, he immediately plays defense against the person he threw to.
Underhand throws.
Ground balls
Left-handed
Make more than one set of lines doing the drill with 6 players to a set.

Squares:

There are four lines (A,B,C and D), each at a point on a square. Player A starts with the ball and runs toward player B. Player B runs toward line C (perpendicularly to player A's movement) and receives the ball from player A. Player B continues with the ball as player C moves toward line D. Player B passes to player C, who advances toward line D. The ball continues to be passed around the square.
 

Variations:

Add more than one ball
Change directions
Left-handed
Make the square smaller for tighter, faster passing

The Weave:

There are three lines of players (A, B and C) at the fifty yard-line facing the goal. The middle line (line B) is supplied with all of the balls. The first players in each line start down the field, the middle line cradling the ball. Player B passes the ball to his left to player C, and runs behind him to take his place at the left wing position. When player C receives the ball, he crosses the field to pass to player A, then runs behind him to take the right wing position. When player A receives the ball, he crosses the field and passes to player B, then runs behind him to take his position, and player B crosses again to pass to player C.

Get it? It's hard to explain, but in broad terms, it's a drill in which the attack wings making long, leading passes across the field while advancing toward the goal. The extra person just makes each line replenish itself.

Variations:

Add 1, 2 or 3 defensemen
Finish with a shot on goal

Give-and-Go:

There are three lines at the 50 yard-line: two at center, and one a wing position. One of the lines in the center is for defensemen, the other center line starts with the ball. The first player in the defense line comes out to about 10 yards in front of the first player in the ball line. The players start down the field toward the goal, and the defender attempts to check the center's stick and to slow him down by body checking. Once the defender has been drawn closely to the player with the ball, and the center senses he's in trouble, he will pass it to the wing. The defense sprints to defend the wing, and when he has been drawn away, the wing will pass it back to center who has sprinted ahead for the goal.

Variations:

Add a pivot point.