Ok, well I really didn't spit all over the plants, but I sure thought someone had when I walked through the meadow behind my house where I grew up. Eventually, I learned that the masses of foam like spit were created by a spittle bug, and knew little more than that until about 10 minutes ago when a Google search led me to a nice little article. The spittle bug nymph, an immature form of an insect called a froghopper, produces this foamy nest. If you stick your fingers in the spit, you'll find the tiny nymph. In this picture, I believe you can see the nymph at the top left had portion of the spittle. Notice the other insects, dead, that are also hanging onto the spittle somehow. Pretty cool stuff. Wikipedia says these guys belong to the superfamily Cercopoidea. It looks like insect taxonomy has changed quite a bit, and Wikipedia explains that somewhat, but I'm still quite unclear. I like spittle bugs though, and here is a great one from Kenney Park.