I do mostly Perl and C programming. Besides pure Perl projects, I find Perl useful for:

• Processing data sets for use in developing/troubleshooting code.
• Automating bits of my build process that would be too tricky with only make and the shell.
• Quick little one-liners to translate crap I'm seeing in the debugger into useful information.
• Hacking together a quick prototype implementation of an algorithm.

Make sure you mention Inline::C and Inline::Java.

Convert::Binary::C is worth its weight in gold when I want to parse a memory dump. I also use it to build up ROM images.