Here at UC Davis we recycle bottles and cans, cardboard and Styrofoam, CDs and DVDs, fluorescent bulbs and sticky notes, toner and inkjet cartridges, batteries and electronics, and even wine corks. And paper, of course.   But what about our pens? Starting today (Sept. 14), we can recycle those, too, and other, selected writing implements — adding more “cool” to UC Davis’recent ranking as the nation’s “Coolest School” in Sierra magazine’s evaluation of sustainability in higher education.   Materiel Management, a longtime champion of campus sustainability efforts, is spearheading our newest recycling opportunity, by joining up with theTerraCycle Writing Instruments Brigade.   “Writing instruments?” Why not just call them “pens?”   Because TerraCycle Inc. takes any type of plastic-encased device: pens, mechanical pencils, markers and highlighters (the caps too!). And those correction tape dispensers that we sometimes use to erase what we wrote! But nothing encased in wood or metal. TerraCycle wants only the plastic for reuse in the company’s line of consumer products — storage bins, for example.