Are you having trouble scanning for particular operators in the code? Keep missing the occasional punctuation characters? Enter the discotheque:
Just run the main command with a Vim regex:
:Disco some_variable_name
:Disco +
:Disco unsafe {\_.\{-}}
When moving the cursor, the colors of the highlighted text will toggle between blue and red. To stop the highlighting, just run the command with no arguments:
:Disco
There's probably less... energetic ways to emphasize pieces of code you're interested in. But it's a fun party trick.