I've got this little character popup that keeps showing up to display accented characters, and slows down typing. I can't seem to find a way to make it go away, and I'm not even sure of it's source (system or added software). I've tried different keyboard layouts (US, Canadian, PC) to no effect, as well as setting relating to the Character Viewer (the big one in System Preferences). The only other utility I could think of was Typinator, but it's not in there either. Seems to occur mostly in Safari when writing in forums like this. Here's the little devil below. Oops. Found it; turns out it is the ApplePressAndHoldEnabled preference. See this page: http://osxdaily.com/2011/08/04/enable-key-repeat-mac-os-x-lion/ I have no idea how I enabled it, but now it's off. You can use Terminal or, as I did, MacPilot or similar utility.