Specify syntax highlighting per file

Can I manually specify syntax highlighting per file? Sometimes it's simply impossible to determine the kind of file just by the filename or by a quick inspection of it (e.g. is .h C or C++, is .m Matlab or Octave....) so it would help if I could manually override it for when Pygments gets it wrong.

Now that my Octave highlighting patches have gotten accepted into Pygments, I would like to be able to use them on bb.