[ErrantX]

This works varyingly well over here in the UK (bearing in mind that we have a lot less tip-focused service industry).

Obviously it works in top-class London restaurants. Anywhere else it tends to vary, I've tried it once in a semi-nice place in Leeds and got an icy stare and an extra wait :) but then it worked great in a grill house when I was in a rush with friends.

By the way; this is fun to do if you are with a group of friends who have never done it before. Once we were trying to eat in one of the London hotels (it was the nearest place and pay day :)) and obviously got rebuffed. It's really shallow but saying "hold on, wait here" and 30s later gesturing them over is worth the looks on your friends faces :)

The best place this has worked for me is a restaurant in a nearby town - not top class but always full. A few £20 "tips" now gets use pretty instant service - because they know we will tip decently afterwards.

Is it immoral etc? I've always thought not, it's just that I value getting a table X much and, most of the time, X is a steal price :)