Press and hold keys for iOS-style accents popup
Here’s yet another iPhone feature that has cropped up on the Mac in Lion. While typing, simply pressing and holding on a key will bring up a popup showing all the possible diacritics (accents, cedillas, etc.) that can be added to the letter. You can then choose from the possibilities by pressing the corresponding number on your keyboard, or by clicking the one you want.
This seems to be a fairly quick way typing accents, and is much easier to use than the old method which involved remembering a number of Option key combinations. It does have one drawback however — it stops you from pressing and holding to write a long line of repeated letters, like thiiiiiiiiiiiiiiiis.
If you don’t regularly type accents, then losing the repeated character functionality might not be worth it for you. In this case, you can disable this new feature using a Terminal command. Open up Terminal (located in Applications/Utilities), paste the following line and press Return.
defaults write -g ApplePressAndHoldEnabled -bool NO
You will need to restart each application for the changes to take effect. Simply repeat the command with YES
at the end to reverse.