Applications :: Creating Open With Menu In Preview?

Is this possible? I find it annoying to have a file open in Preview and then having to either locate it or save it to allow me to open it in something else (like Acrobat or Photoshop). An example: I have just been sent a pdf that I need to open in Acrobat pro to merge with another one. Using Entourage the only things I can do are save or open, opening it results in it opening in Preview - which is usually what I'd prefer, but in this instance, I need to edit it, so I have to save it somewhere and then open it again from Acrobat. Preview is great, don't get me wrong, and not having to open up the whole program first in most cases is brilliant, but sometimes it's a pain that I can't subsequently open the file I'm previewing in a different program.