No kidding about the getting everywhere. I blew dust out of a couple of towers at work and made the mistake of not using any breathing protection. I was blowing grey junk out of my nose for the rest of the day. Eww. Last time I make that mistake.LOL . No my eMac sits on a desk so I haven't a clue where all the dust is coming from Yeah it is probs better to use compressed air but, I didn't want dust getting everywhere.
Oh, and incidentally, I think the reason that Apple's newest computers seem to be less dust-prone is due at least in part to the fact that they now use big, slow, variable speed fans. The wider area of effect and slow airflow rates make the dust less likely to stick on its way through.