Apparently, the first meteorite from the fireball over Wisconsin has been found: a pair of brothers discovered a small chunk of the bright meteor that burned up over the midwest skies Wednesday night.
It certainly looks like a meteorite (click to embiggen); the outer blackened fusion crust is from passing through the air, and the interior has the gray, grainy structure in common chondrites. The cube is one centimeter in size and is used in photos like this to give scale.
Pretty cool. There may be thousands of such meteorites lying on the ground in Wisconsin right now; the meteoroid itself was probably a meter or so in size and weighted about a ton. Meteorite hunters are already there searching, and I hope that most of the fallen rocks will be sent to researchers for analysis.
Falls like this are very important scientifically. Having a lot of eyewitnesses means the path and therefore the orbit of the rock can be ascertained, and many times such meteoroids are part of a family of such objects; all on related orbits and probably from the same parent body. When we get samples of the meteorites that means we have samples of an asteroid!
So if you live in that area and find something suspicious, take photographs of it where it is, then carefully put it in a baggie or box (use gloves if you can so you minimize contamination) and contact a local University. The vast majority of rocks found this way aren't meteorites (we call 'em meteorwrongs, haha) but it's worth making sure.
Image: Terry Boudreaux, submitted to Rocks From Space by Michael Farmer.