C call trees

[Mike Morris]

    I am currently searching for software that will produce
attractive yet functional call tree diagrams from C source modules.
I have recieved some literature on C-DOC (documentation tools) by
Software Blacksmiths and C/Analyst by Cater Software and both appear
interesting.  Has anyone out in netland tried either of these products
or possibly some other nifty tool?   Thanks in advance.
-- 
Mike Morris, Strategic Locations Planning     {hpda,pyramid}!octopus!slp!mikem