Using grep (or some other tool) to highlight, instead of grepping?

Hi all,

most of you will be familiar with colored grep output like

 grep --color=auto

I was wondering if there is a tool that will allow me to simply
highlight whatever I am looking for without actually grepping. I could,
of course, use --context=999999, but that would be a waste of memory &
processing time, especially with larger files.

Any ideas?


Thanks,
Richard