...if its ok to go off topic for a second, it depends where you are, now in the UK its always a bit of an awkward thing to work out (maybe its different in London, I don't know) if you're out with a group because some people give a tip, some don't ever tip, there is no standard percentage, some restaurants say service is included, some say it isn't, sometimes it depends on how many you are, some would only tip in exceptional circumstances...its a nightmare!