We sometimes like to have a candle at the dinner table. I have always wondered why candles don't smoke much until you blow them out:
And the chaotic patterns made by the smoke are intriguing as well.
I'll post a little piece on the technical aspects of photographing smoke in the next couple of days over on curtisjudd.blogspot.com. Oh, and if you ever need a little help making better images of the things you want to sell on e-bay, drop on by for a quick how-to on product photography.