Tinkercad link: https://tinkercad.com/things/9F4HBo22TMx-day-22-3d-star
Thingiverse link: http://www.thingiverse.com/thing:152528
Settings: The clear ones were made with a Replicator 2 on MakerWare "low" setting, with 10 stars taking just 34 minutes. The blue ones were made with an Afinia H-Series on their 3D sofware's .2mm setting, and otherwise default settings and "normal" speed, with 9 stars taking 56 minutes. To be fair, MakerWare's "low" setting is a .3 mm setting and comparable to Afinia's "fast" on that resolution.
Technical notes: I did not have good luck printing full stellated dodecahera at this size, which is why I cut off the top and bottom. This allows much better adherence to the build platform. In the end I think this is actually better because they look much more like stars. The stellated dodecahedra came from Mathematica's PolyhedronData command. Teacher note: alas, the picture above overestimates the number of B-and-above grades on my first calculus exam by 200 percent.