I have this in my .vimrc:
nnoremap ; :set invhlsearch<CR>
This way, ; will toggle search highlighting. Normally, the ; key repeats the latest t/T/f/F command, but I never really used that functionality. I find this setting much more useful, because I can change search highlighting on and off very quickly and can easily get a sense of where my search results are, at a glance.