To introduce myself and act as an icebreaker, I used the toilet paper game (like ball pass or string game, but with consequences...):
Bring in a roll of toilet paper. Hold one end of the tiolet paper and throw the rest of the roll to a student. After the student catches the toilet paper roll, he/she must answer a question (i.e. What is my name?, How was your weekend?, Where am I from?). After answering the question, the student proceeds to latch on to the toilet paper and throw the roll to another student (so both I, and the first student, are still holding the toilet paper). Then ask another question to the new TP recipient, who also holds the paper and then throws.
If the toilet paper breaks during any launch, then the thrower must wear the toilet paper as a tail for the rest of class! If it doesn't break, just continue on. Just begin again if it breaks. In case it doesn't break, just go tear it :) 5th grade kids got a big kick out of this.