Highlighting
When I read text on my computer, be it emails, documents, web pages etc - any text. I click and drag my mouse and highlight it, turning the text blue Blue.

I have been doing this for so long, that i no longer notice I do it, although I have been shouted at by colleagues for the constant clickity click noises when I read emails.
(Dan dan dan They tik urh jerbs!!!, Wed 7 Jul 2010, 9:19, 8 replies)

I do the same
Drives my wife insane.
(yokelrobin THE NERD WHOSE HAIR DEFIES GRAVITY/FASHION, Wed 7 Jul 2010, 9:24, closed)

I do it to...
In fact, I had highlighted the first line of your answer, then when I read it, I tried not to with the second line, and couldn't!
(The Kwyjibo A big, dumb, balding North American ape., Wed 7 Jul 2010, 9:46, closed)

Your colleagues shout at you for clicking your mouse?

(TheManWithThePlan cussed your mum on, Wed 7 Jul 2010, 9:55, closed)

I refer you to
bamboozleds response below

my missus does this
when she wants to show me something on her screen - it's fucking annoying
(bamboozled Can hear you getting fatter, Wed 7 Jul 2010, 10:54, Ignore, Reply, I like this!)
(Dan dan dan They tik urh jerbs!!!, Wed 7 Jul 2010, 11:02, closed)

I do this with badly designed websites
You know the ones. Yellow text on white background, that sort of thing.

But have been training myself to use Readability instead.
(Cloudane, Wed 7 Jul 2010, 10:13, closed)

my missus does this
when she wants to show me something on her screen - it's fucking annoying
(bamboozled Can hear you getting fatter, Wed 7 Jul 2010, 10:54, closed)

Can't you just press ctrl + a?

( Bob Todd whee, Wed 7 Jul 2010, 13:09, closed)

its not as much fun
you need to click an highlight where you're reading.
(Dan dan dan They tik urh jerbs!!!, Wed 7 Jul 2010, 13:15, closed)