Japan-based writing utensil manufacturer Pilot struck upon a cool idea: Why not make pens out of recycled water bottles? Their resultant B2P (Bottle-2-Pen) units come in both gel and ink varieties, made from 89% and 86% recycled plastic bottles, respectively. And they've designed the pens to visually evoke water bottles as well:
There's no mention of the pens being recyclable a second time, but they are refillable.
A is six bucks and change, while the run closer to nine bucks.