For my 9 year old son we decided to have a "PS2 & Pizza" party. We are borrowing 2 PS2 games.
We will also set up a game table (pool, pong, foosball). We will divide into teams of 2 boys (10 total) and they will play for a set time. When the timer goes off, we will tag-team it and send in two more on each game. The boys who are not on PS2 are welcome to play Game Boy, Atari, the game table, or basketball while awaiting their next turn. We will break for pizza and for cake. As for gifts...it was mentioned that the birthday boy was saving up for his own new Video Game System. For goodies we plan to give them each a batch of glow in the dark bracelet-sized that they can join any way they choose (found at dollar store in a tube 15 for $1).