I just installed SMS Popup this morning. So far I'm loving it. When you get a text while your phone is asleep, it wakes it up, and shows you a popup with the contact and message. By default it has buttons for "delete", "clear" and "reply" on the popup (I took these off though so I don't pocket reply to messages). And after replying or clearing, it reverts back to the lock screen and then sleeps. You can set it to only show popups for certain contacts, or for all, and it lets you customize the led and vibrate notifications as well. Pretty sweet app so far. I believe there's a similar app for email popups.