A tiny Python script that finds the total lines of code in a directory tree.
python sloc.py cpp h
will find all files ending with .cpp and .h in the current directory tree, count how many lines they each have, and tell you the total.
python sloc.py -d /some/arbitrary/path py rb
will find all files ending with .py and .rb in the /some/arbitrary/path directory tree, count how many lines they each have, and tell you the total.