In photography as well as in paintings (especially those from the middle ages, where a lot of symbols were used), the position of the hands often means a lot; does anyone know a list of all those meanings, or could you maybe give a few of them?
I looked a bit for symbolism, but couldn't find anything.
At least I found this, containing several useful tips: How to Pose Hands in Portraits
Requires registration, but appears to cover what you are after:
Hand gestures play a crucial role in religious art. An examination of Judeo-Christian art finds an ecclesiastical language that is concealed in metaphors and expressed by unique hand gestures. Many of these hand signs convey messages that are not familiar to most people admiring these paintings. Investigating the history and classifying some of the predominant hand signs found in Judeo-Christian art might serve to stimulate discussion concerning the many nuances of symbolic art. This presentation examines the meaning behind 8 common hand signs in Judeo-Christian art