According to this infographic posted on ragan.com, pretty darn germy and gross -- 100 x germier than most kitchen tables. The biggest contributor to the germiness -- eating at our desks. Only 1 in 5 of us cleans our desks before eating, so maybe we'd all benefit from treating our desks a little more like our kitchen table and wiping them down after lunch.
Many thanks to Erin Mantz for sharing this with me. I'm going to grab some Lysol wipes right now.