best way to upload and rename an image

[eluser]llbbl[/eluser]
[quote author="FuzzyJared" date="1193190081"]that does make sense.
[/quote]

if you want your server hacked use FuzzyJared's code.

Basically what you want to do is:

1) don't let the user access the images via the same name or similar name as the original file name.
2) upload the images outside the web root
3) use a php script to view the images

If you can't do 2 or 3 than:

4) check for file extensions
5) use GD to verify it is an image
6) upload the images to a subdomain with php and cgi disabled