Well,documentation...
For the moment, I will put here just the stuff from usage() and some comments:
Online: ./vncrack -h target.host.com -w wordlist.txt [-opt's]
Passwd: ./vncrack -C /home/some/user/.vnc/passwd
Windows interactive mode: ./vncrack -W 
        enter hex key one byte per line - find it in
	\HKEY_CURRENT_USER\Software\ORL\WinVNC3\Password or
	\HKEY_USERS\.DEFAULT\Software\ORL\WinVNC3\Password
Options for online mode:
-v      verbose
-d N    Sleep N nanoseconds between each try
-D N    Sleep N seconds between each try
-a      Just a funny thing
-p P    connect to port P instead of 5900
-s N    Sleep N seconds in case connect() failed
Options for challange/response intercepted by PHoss:
-c   Copy and paste from PHoss
-r    Copy and paste from PHoss
  
In Windoze interactive mode, you are prompted for 8 lines of 2-digit hex data. This looks like this:
2F 98 1D C5 48 E0 9E C2You may use 'echo -e "AF\nFE\n..."' for this task and pipe it in VNCrack. It is the stuff you find in the registry keys.
Version stuff: This proggy replys to the server's version message with bouncing back the same one. But I suspect this program will not work with versions greater then 3.3.