Populating file input elements with Javascript

I understand that for security reasons normal pages can't use Javascript  
to enter file paths/names in file <input> elements, but is there any way 

to achieve this at all, perhaps using user javascript, widgets or local  
pages etc?


And just out of curiosity, is it likely that Opera will at some point  
relax Javascript security model for user javascripts (to allow things like  
manipulating the DOM in framesets where different frames come from  
different domains - currently blocked to prevent potential XSS exploits)