Ohcount is the source code line counter that powers Ohloh. Ohcount supports over 70 programming languages. Ohcount can also detect popular open source licenses such as GPL determine if code targets a particular programming API, such as Win32 or KDE.
Great app, very fast. The fact that it tells you how many lines are just whitespace/comments and how many are actual code is ingenious. Also, there's a package in the ubuntu repositories for it .
Quick and clean - and good to see it's an active project too.