A basin for all nations

In Kiran Desai's The inheritance of loss, when one Indian immigrant living in New York City hears of another's plans to return home, he tells him:

"You're making a big mistake. Thirty years in this country, hassle-free except for the bitch-witch, of course, and I have never gone back. Just even see the plumbing," he indicated the sound of the gurgling toilet behind him. "They should put their plumbing on their flag, just like we have the spinning wheel--top-class facility in this country."

I'm not a big fan of objects on flags, but if you were going to take Mr Kakkar's advice and put an image of something on your country's flag, what would it be?