if I've got a few documents open, I'd like to be able to save all (to their respective locations) with one menu item (and a subsequent keyboard shortcut)
Great idea. Personally close the document(s) after save. Would be great if "Save As" could be treated the same. Especially TIFF files and allow the TIFF dialog box to confirm the type of TIFF for the first file being saved with that setting being applied to all open files.
Jeffrey, I'd like to see the Save All function as well. I often take photos in portrait mode then want to stitch them together in a panorama. The camera natively saves them in landscape mode, so when I open them Photoshop rotates the photos to portrait mode but won't allow the panorama stitching until they are all saved again. So I either have to save all one at a time or close them out, then rotate them en masse in Windows Explorer, open them again in Photoshop then stitch. So I'd like to see a Save All that leaves the documents open. I can also so the value in a Save and Close All feature as well, but for different reasons.