I've released highlight 0.2-2 to CRAN. This release adds the possibility to control the font size of the latex code generated by sweave (when using the driver that is provided by highlight)
For example, this C++ code (using Rcpp) will be highlighted in tiny size.
<<lang=cpp,size=tiny>>= double square( double x){ return x*x ; } SEXP foo( SEXP xx ){ NumericVector x(xx) ; return sapply( x, square ) ; } @
This is something we had to do manually when preparing the slides for useR! 2010