I found this in a few different places around the 'net - hopefully it's helpful:
Fax Tips
Here are some useful tips for working with Fax and Image Viewer:
- Typing Ctrl-I in the picture viewer will bring up the property sheet for the image (doesn't work in slide show).
- Typing DEL in the picture viewer will delete.
- Holding down the Ctrl key in the picture viewer enables "panning" (hand cursor)