Send file from Amazon S3 to ActionController::TestUploadedFile

Hi,

I'm writing a script to import several data in my application. I use
ActionController::TestUploadedFile (from attachment_fu setup with an
Amazon S3 account) to upload image.

Actually, I have to give the path of the image file in my filesystem
to the method TestUploadedFile but I would like to take the file from
an Amazon S3 account.

The way I can do that is :
1) Download the file from Amazon S3
2) Save it on my filesystem
3) Add it to my app with TestUploadedFile
4) Remove the file in my filesystem

Is anybody knows a better way to do it (without using my filesystem) ?

Thanks for your help

Adrien