I'm one of those anal people, and when I get an IM and read it on the screen, it's annoying to have to open the IM window manually with the mouse (when I don't need to read it again) just to stop the button's accursed blinking!
It would be oh so nice to be able to hit Ctrl-E Ctrl-E or something to just knock out that blink.
Unfortunately the obvious shortcuts are taken
Ctrl-I is of course your inventory while Ctrl-M is the map. Ah well.