Give extreme timeframes. If someone needs something done, tell him or her it will be done in a week, and hand it to them 3 days later.
I got told about this one by a senior colleague (sp?), and it is the best lesson i ever learnt: People are pleased when you finish 'early' and not angry when (inevitably) your timeframe was over-ambitious and things take longer than you expect! Brilliant.
It also helps combat the extreme under-estimation of timeframes by non-programmers: "All you have to do is click a button! Why will this take so long!?" "Well, first i have to build the button..."
Just a something something...