In the toolbar is a button with an icon that looks like the nib of a
yellow highlighter. The tooltip says "Toggle Mark Occurrences".

Or, right click in editor background, choose "preferences" and navigate
to Java, Editor, Mark Occurrences.

I have to learn not to post before the caffeine kicks in.

Let's try again...

I am pleasantly surprised to see how intuitive Eclipse is. Even
thrilled. Frankly, I expected the learning curve to be steeper (like
Java's).

The one thing that bothered me early on is that when I double clicked
on a word (say, a variable) all the same variables would also
highlight (and there are some very useful markers along the right
edge). All this is nice and dandy, except that there was no way to
turn it off. My evasive maneuver was to double click on something like
'main' in order to reduce the distracting highlighting all over my
screen. I can't work when my screen looks as a Christmas tree.

 "Be careful with what you wish, because it may come true".

Now, it seems that Eclipse read my mind, and its feelings are hurt for
me being such an ingrate.  Like any self-respecting Catholic or Jewish
mother, Eclipse is giving me the guilt treatment. The highlighting is
entirely gone. Maybe I am using a different editor now?

This is the one Eclipse feature which is not obvious...

-Ramon