You can use the VOCPhax graphical interface to view the g3 faxes recieved through VOCP and mgetty. Your VOCP system is already configured to receive faxes but if you may wish to see the section of setting up faxing with VOCP anyway.
VOCPhax presents a friendly and intuitive graphical interface to view and send faxes. When VOCPhax is launched, it will present a preview of all the faxes found in the default incoming fax directory (/var/spool/fax/incoming/ by default). These previews are miniature versions of the g3 faxes found in the inqueue.
You can select a particular page by left clicking it once. Double-clicking a preview will open the view window, within which you can zoom in to see your fax up close. You can re-order the pages by drag & dropping them, although this is only really useful in the case of the out queue (when sending faxes).
The main window's menus are:
File->Open (open a g3 fax file)
File->Create (create a fax from a file in another format, such as jpeg, gif, xpm, ps, etc.). Useful for sending.
File->Delete to delete the page
File->Export to export the fax to another format (simply choose a location and file name with an appropriate extension, like /path/to/blah.jpg).
File->Send Queue (send the files in the out queue)
File->Quit (not sure what this one does... ;) )
In Queue->preview (show thumbnails of the faxes in the in queue)
In Queue->Select dir (select a directory in which to look for incoming faxes)
In Queue->empty (delete all files within the queue)
Double clicking on any of the thumbnails will open a second window in which you can view the fax page at a larger scale. In this window you can drag the image around and zoom in or out. Most of the options are pretty straight forward - explore and play with it, if there's something you can't figure out, let us know.