Sorry if someone has already has this grenade idea or name, but it just was so simple.
The grenade does have a pin, but it is optional.
The grenade will look like this when it is finished:
Step 1: Parts List
White Connectors - 2 or 3
Red Connectors - 16 or 20
Orange Connectors - 8 or 10
Yellow Connectors - 0 or 2
Gather up all the parts and then continue.
Step 2: The Shell
Just follow the pictures.
Step 3: The Rubberbands
Follow the pictures, yet again.
Step 4: The Filling
Follow the pictures, don't forget.
Step 5: The Pin (Optional)
... well, you know what I was about to say.
Step 6: You're Done!
You have finished the grenade! Now throw it at your neighbors!