A lot of those excuses suck hard. e.g. "One day i didnt go to skool and the teacher found out lol". I mean.. *sigh*
Anyway, I don't really have any good ones off the top of my head. However, since my class has been together quite a while (12 years) we have a good collection of in jokes. One of them stretching back to when we were 8 and one of us wasn't at school when our dear old teacher called the role. When the teacher asked if he was sick she got some kids saying yes and others no.
Eventually.. Somehow.. the message got across that he was "On the thing". Like in refrence to a school trip or something ("On the inter-schools swimming trip").
And from then on if somebody is sick, on a trip or wagging we use the cover: "He/she's on the thing". The teachers often look puzzled and futher attempts to find the real reason always fail.
But now "On the thing" is starting to creep into other areas.. such as homework. "Where's your homework?" "Sorry, last night I was on the thing".
</slightly related anicdote from my short life on this planet>