iPhone (Jailbroken): One of the annoyances with the iPhone's banner notifications is the fact it blocks the top of your screen. CoverMeNot is a simple but useful jailbreak tweak that resizes your screen slightly so that banner notifications don't get in the way of what you're doing.
It might not sound like much, but it's annoying when banner notifications block off your screen. With CoverMeNot, the notification resizes your status bar, pushes the screen down slightly so that the notifications don't get in the way. You can find CoverMeNot as a free download in the ModMyi repository.