i use a datavac everyday at work and i can say it is much more effective and efficient at cleaning computer hardware than compressed air. i've even used it to dust other things at home, like action figures!
Oh good, people have the sense to vote for the MetroData on this poll. Everyone voted for that POS thing on the other one that didn't have enough power. Forgot the name because it isn't worth remembering.
Don't bother buying cans of air anymore. They're a waste of money because they run out way too quickly and are only effective when >50% capacity. The datavac is a great product, more efficient and around the same size. The only downside is that it's loud so it isn't suited for some IT office environments, institutions or libraries.