Windows 7 - Picture Viewer?

Alright, here's my current dilemma.

People send emails to my Yahoo! Mail account that have pictures attached. Not a problem, right? But I use Firefox, and for some reason Yahoo Mail is different from most sites, and makes Firefox show the "Open or save" window.

I could just save them and open, but that's tedious and I want to be able to open them right off the mail.

However, I'm aware that Windows Photo Viewer, like in XP, is not a single EXE file that you can run.
But I want to have my pictures just open in Windows Photo Viewer straight off Firefox.

is that possible? Is there a way to make a shortcut using rundll32, or something?
Or would Vista's Photo Viewer EXE work on Windows 7 (like Paint and Wordpad do?)

I guess I just don't want to have to resort to something like Ifranview just to open pictures that people email me.

Here's an idea, not sure if it will help, but just may be. Create a folder in the "Picture Folder" in my library, then right click on the photos in your email account and save them to that folder; that way you can view them in whatever photo viewer suits your fancy. This is probably not what you want, albeit I tried the ones I have and couldn't get them to do what you are looking for.

That's exactly what I didn't want to do - save and reopen.

I tried WindowsPhotoGallery.exe from Vista... gives some stupid error about d3d9.dll being invalid. (Could be because that was 32-bit Vista)