Techradar posted a review on 5 Bluetooth iPad keyboard

The on-screen keyboard in iOS does the job for short bursts of text, but if you want to use your iPhone, iPad or iPod touch for long-form writing, you're better off using a discrete keyboard. Even for shorter things, such as text messages, instant message chats or brief emails, a separate keyboard speeds you up no end. As well as actually typing, you can manipulate your text more quickly because iOS lets you use shortcuts for commands such as copying and pasting, and Shift+arrow keys to select text. You can also use the arrow keys on their own to move the cursor around, so no more dragging your finger and squinting at the on-screen magnifier to position it. Apple sells a dock for the original iPad with a keyboard attached to it, but a Bluetooth model gives you more freedom, both in terms of the devices you can use it with (these keyboards should work with Macs and PCs, too) and when it comes to your setup.

  Buying Guide: Best Bluetooth iPad keyboard: 5 reviewed