Spitting on people is a disgusting habit. It's dirty and (possibly) disease spreading and not very nice to do. But let's face it, gobs of squishy stuff flying through the air is fun. So, let's science it up a bit. What if instead of real expectorations, you flung awesome spherical polymers at your friends and/or coworkers? What if you grew them yourself in the comfort of your own cube. We're here for you: get thyself some Spitballs!
Spitballs start off as small hard little spheres. Soak them in water for about 4 hours (or overnight for best results) and they will absorb water and grow up to 200 times their original size. Spitballs are now ready for war. They are slimy and squishy. If you throw them gently, they will bounce. If you throw them hard enough, they will explode into mushy pieces. And here's the best part about Spitballs: when the war is over, collect all the whole ones and let them dry out. They will shrink back to their original state and can be reused at a later date. Spitballs - grow 'em and throw 'em.