Hmm it didn't work. But never mind, I don't feel like emailing GoDaddy again. I'm just encrypting my pictures and then I'll write a script to decrypt them. Thanks anyway! I guess this is what you get for cheap hosting.
Christ, GoDaddy.com support is usually great any time I call them up
The HTACCESS method above does work as I remember using it some time ago. Although I believe you may need to restart internet services - not 100% sure on that though and I'm not sure on the code given above.
Might be worth a google search to save you the bother of having to encrypt and decrypt.
I'm actually almost done the encrypt/decrypt. I have an excellent function that adds the initialization vector right to the end of the file so you don't need to store it in a database. If it doesn't work though, I will try till I get it (or get too pissed to continue). Thanks for your help!