I own one of these, and they're the exact tool for the job when you don't have, or would rather not use a light stand to mount a light source.

I just saw this video over on the Fstoppers blog and thought "yes, I'm going to try this for a shoot later this week!"  Especially since clouds are in the forecast.     [removed iframe during malware-safe restore] Speedlight Mastery Trailer from Damien Lovegrove on