Laying the iPad flat in landscape orientation makes typing on its touchscreen relatively easy once you get used to it, but what about typing when you're holding it in your hands? If you've got hands like a basketball player, thumb-typing on the iPad in portrait orientation probably hasn't been a problem for you so far. For the rest of us, we were hoping for a better solution. In iOS 5, that solution is here: Apple calls it the split keyboard, and it's pretty awesome.
The old button to show/hide the keyboard has gained a few more options. Tapping and holding the button will bring up options to Undock or Split the keyboard, as shown below.
Undocking the keyboard allows you to move it up and away from the bottom of the screen to wherever you want it. This becomes more useful when the keyboard is also split, which results in two smaller mini-keyboards toward the edges of the screen. These keyboards allow you to thumb-type on the iPad's screen, almost exactly the same way you'd type on an iPhone or iPod touch. Restoring the keyboard to its normal configuration is simple: tap and hold the same icon you used to split it.
There are two other ways to activate/deactivate the split keyboard. The first uses that same button in the lower-right corner of the keyboard, but instead of tapping and holding, you can swipe up from this button to undock and split the keyboard, then swipe down to dock and merge. The other way to activate the split keyboard is by using two fingers, one on each side of the keyboard, and swiping outward toward the iPad's edge; think of this gesture like you're ripping the keyboard in half with your thumbs, because that's exactly what you're doing. Merging the keyboard again uses the same gesture in reverse.
This may seem like a non-essential feature at first, but if you're like me and you do a lot of on-the-go typing on your iPad, you'll find yourself addicted to the split keyboard fairly quickly.