Wow, I couldn't disagree with you more, Cris.

First of all, a waiter/waitress is doing a hell of a lot more than "pick up a plate of food and walk 20m." Have you ever waited tables or known someone who does? Do you know how much they get paid?

I have two more things to say about your reply:

"telephone engineer" - does not get tipped (sorry!)
"wedding photographer" - pretty sure should be tipped

So is this a grudge you're holding that makes you not tip? I go into people's homes and fix their computers. That's pretty damn personal too, but I don't expect to get tipped for it. I'm also making far more than an minimum hourly wage for that service.