Whenever I download a PDF or video from the internet and I try open it directly instead of saving it to the disk, it always ends up on the desktop. For example, I download a PDF, choose to open w/ "Preview", and the file stays put on the desktop. I don't like a cluttered desktop, and don't like trashing things I just want to look at once. is there a way to make Firefox for OS X save these files to a cache or temp folder or anything? Thanks in advance.