Just downloaded PHPCallGraph and tried it out on my Linux system. I got the following errors:
[root@r3-mobile bin]# ./phpcallgraph -o phpcall.ps /media/Dos/AcctPybl/server/Lib*
Parse error: parse error, unexpected T_ARRAY, expecting '&' or T_VARIABLE in /root/projects/cat/phpcallgraph-0.6.4/src/PHPCallGraph.php on line 82.
2008-01-15 19:28:13 UTC in phpCallGraph