This is so cool I want one!!! Candle Cannon
The Discovery Channel Store used to sell small handheld size versions of this. You could feel the air blast from about 20 or so feet away. Haven't seen them in a couple of years tho.
I have a small one. Bought it at http://thinkgeek.com Yeah, here it is.
It's pretty cool. You can blow someone's hair back from 20 feet away and no one standing in between will feel it as long as they're out of the direct path. Never tried blowing out candles, but I'm sure it'd do a great job.