I love public transport in Hong Kong. As celebrated in this magazine earlier this month, it's cheap, fast, efficient and safe, and it's always there when you need it.

In fact, our MTR, bus, tram and ferry services are so good that Hongkongers have come to feel at home on them. A little too much, unfortunately. Some things, let's be clear, just shouldn't be "public" on public transport. Applying make-up and sleeping I can understand, but I tend to feel a little bit nitpicky over nose-picking. Zit-squeezing and facial and nasal hair plucking leave me cold. You try to look the other way, but you still know it's happening.

Last week I encountered a new public transport low that I had heard was on the rise: toenail-clipping.

There is something extremely weird about protein growing out of our toes, even if it happens to each and every one of us. And, of course, we'd look like we'd stepped out of Where the Wild Things Are if we didn't keep it in check. But that's a task for behind closed doors; nobody should have to sit in the vicinity of shameless nail-clipping.

Worst of all is when toenails ping, sputnik-like, out of the clippers. As the offending cutaneous missile flies through the air, there is an agonising moment as you face up to the possibility that it might land in your lap, or your hair. And lest you want a new taste sensation, it's best to keep your mouth shut.

Whether on planes, trains or automobiles, a gentle plea, dear reader: keep your hands to yourself and your feet in your socks.