I have rigged a model of a soldier and weight painted the right half of him. Is there any way I could now autmatilcy get the other side rigged too?
In Weight Paint tool shelf under Options there is a check box for X Mirror. Check it to paint automatically. In your case, you need to repaint it on one side with X Mirror checked.
But there are two conditions! Mesh object must be a mirrored mesh, an exact copy. And bones need to be an exact mirrored copy as well, with proper .L and .R Armature item name.
Thanks for the response, I will start painting then