"When you open a file like that in Photoshop, you can easily know its' location in your Finder."
That's the problem ... the files are invisible, there is no way to click on them or a documents tab.
If you start with Finder => Pictures => iPhoto Library => error message: "Could not complete your request because Photoshop does not recognize this type of file." This is really silly ... I should be allowed to manage my own files on my own computer. Files don't appear in Bridge, either.
The folders have file names like: "8RFIXHYyQcqK15+QPf%8Kq" Usually each folder has one image. None is visible unless I use the 'Save As' control.
I access these files by opening an iPhoto image in Photoshop then using the 'Save As' control which shows view of hidden iPhoto library w/ Photoshop files. It is hard to use the 'Save As' control to manage the files: it's a Save As function and not much else.
The files and folders simply will not appear in Finder ... or in iPhoto ... or in Photoshop.