If I have to use a Keurig brewer (I don't have a choice at my client's facility), I use the mesh bottomed One Cups instead of K-Cups, which doesn't eliminate the waste but sure does reduce it significantly. Plus the San Francisco Bay coffees are better quality than Keurig.
At home I use pods, which I make myself. I have two Krup's Home Café units and a Senseo.
Having a dirty mind makes ordinary conversations much more interesting