When your late for a meeting it sends the signal that you dont care, so a late meeting should be avoided at all costs. I always plan to be there 15 – 30 mins early so to avoid late meetings and just because your early it doesnt mean its time wasted. The early time can be used to think about the meeting ie plan what you want out of it and what a successful meeting outcome would be, mobile email means the time can be used for email triage, maybe make a call to some people you have been meaning to catchup with or just take a breath and think about life.
Life does throw you curve balls so being late is something that can still happen, but always ring as soon as you know you will be late so the person is not waiting and not wasting their time, it gives a chance to reschedule because a rushed meeting is a bad meeting and if its a lunch meeting you should always be picking up the bill to show the person that you value their time.
One other final thing, if your in a meeting dont answer your mobile phone, if there is a must take call coming through then have the respect of warning the other people that your expecting a call and that its important
Love to hear other suggestions