This is interesting bug and might lead you somewhere (i have a hopes for duping), i didnt find a way to use it yet, but maybe it is possible! So...
Take any item (for example from your inventory) by clicking a mouse on it like you are going to drop it and,, then click escape to open menu and logout. then if you login again you will be able to notice this item even on selecting character screen (!). And after logining you will be still holding this item! I tried dying when holding item for example, didnt help. Maybe some crashes or game changes will get two items to you - one back inventory and one still holding on mouse.