you mean the file permissions? or do you mean through php.ini?
if it's the file permission, but i don't think so, you have to use chmod('filepath', 0777);
Just wondering, but aren't the files in the tmp directory deleted after a while. that way there's nothing to worry about. when you wonna keep em, you should store em somewhere on your server (e.g: a folder called /images/)
the last time i wrote an upload script, i copied the file to the image directory after checking, but i didn't remove them from the tmp directory
Greetz,
UnrealEd