In iOS if you wanted to accept the suggestion you pressed the spacebar. if you didnt, you tapped the word. Now that much more simple on a device where your fingers are already located close to the screen. In Lion, if you want to accept the change, you press return ( simple enough ) but if you don't want to accept the change you have to stop typing, move your hand all the way over to the mouse and click on the 'X'. Personally this seems like way too much touble just to type the spelling you want. My question is is there any shortcut you can use to dismiss the autocorrect?