is_uploaded_file is a register_globals artifact, and shouldn't need to be used with the $_FILES array.
? That is untrue. You should always use it.
How would $_FILES get populated with invalid data (that is_uploaded_file would catch)?
register_globals = 1 http://example.com/$_FILES['file']=foo
See:
http://sean.caedmon.net/tests/files/index.php?_FILES[foo]=bar http://sean.caedmon.net/tests/files/index.phps
http://sean.caedmon.net/tests/files/http_post_files.php?HTTP_POST_FILES[foo]=bar http://sean.caedmon.net/tests/files/http_post_files.phps
(PHP 5)
*shrug* it wouldn't hurt, but I persoanlly see no need for the recommendation.
S
