When "Please be a fart" turns into "Please be a... uh-oh" and the next stop is a public restroom, I take drastic measures to safeguard myself against the germs that infest every public nook and cranny. And those paper seat guards?!?!? Please, those damn things don't help at all and they never stay in place once the deed's been done and I have to wipe my ass. Not to mention, the really dirty public restrooms don't even carry the seat guards or the dispenser is present, but the guards haven't been in stock for years.
This is why I don't travel without a can of lysol, my friends. (Update... Nowadays they make nice, convenient disinfecting wipes.) It's as important as duct tape, trust me. It would take way yonder too long to tape the seat and that little area of the rim where Mr. Johnson likes to hang out. So I douse the rim and the seat with copious amounts of lysol, wipe them off with toilet paper and reluctantly take a seat to do the deed as quickly as possible.
Thankfully, this doesn't happen often at all. I only had to take drastic measures once this summer after a suspect breakfast somewhere around Detroit. I know I'm not the only one who encounters these issues, but I may be the only one stupid enough to talk about it on a public... website.