If you're like me (God help you if you are), you're lazy. Here's a few tips from think's I've learned in my short time on this earth:
1. Look Busy: Having papers spead all over your desk helps, as do pencils which are widdled down to the eraser. If you have to walk somewhere, keep your head down, and walk quickly (is also works if you're trying to aoid being called over to do work, NEVER MAKE EYE CONTACT!). Carrying clipboard with you while moving around also helps out.
2. Speak Quickly: If they can't figure out what you said, they'll assume you don't have the time to explain it.
3. Hide: Find a good hiding place. A couple good examples are under a desk, in the air vents, or a janitor's closet.
4. Break a Limb: Pretty self-explainitory, no?
5. Excuses: There's nothing like a good list of excuses. Ones like "I would, but i have to babysit my mother's aunt's friend's sister's goldfish." works well.
and Finally...
6. Never Leave Your Room: If you don't leave your room, you can sit at your computer and node at everything, no one will bother you, and as long as you have an ample supply of rations, you can survive for quite a while.
:P