Mac OS X Lion introduced a new, iOS-like context menu when you press and hold a key that enables you to choose a character from a menu of options. If you are on Lion try it by pressing and holding down 'e' in any app that uses the default NSTextField for input.
It's a nice feature and continues the blending of Mac OS X and iOS features. However, it's a nightmare to deal with in Sublime Text if you're running Vintage (Vim) mode, as it means you cannot press and hold h/j/k/l to move through your file. You have to repeatedly press the keys to navigate.