While the iPad has a (very usable) touch-keyboard as standard, the down-side of using it for any prolonged period (e.g. for anything more than entering web-addresses, completing on-line forms or search chains) is that you 'lose' a considerable amount of screen space to it; therefore if you are writing emails of more than two lines, composing documents or updating your latest on-line journal entry, this creates an annoyable level of inconvenience.
The Tecknet bluetooth keyboard is only one such example of a number of equivalent offerings on the market place but is - in my humble opinion (having used one or two other such pieces of kit that purport to do the same job) - the best that I have used so far.
It has a 'hard' keypad ( as opposed to a soft gel/rubber keypad offered by some inferior competitors) with full Mac keyboard equivalency (a major advantage if - like me - you are a reguilar iMac or MacBook user). It's bluetooth connectivity means it requires no 'hard' connection other than the 'slide- in' iPad holder (which moves through a 100 degree [plus] angle) giving the resultant look of an extremely cool notepad. Once your work is done you can keep the keyboard physically coupled to your iPad whereby it serves the job of an extremely effective hard screen cover for your device.
I have been using my keyboard for a little over 2 months now (all blog entries to date have been created using this 'add-on' device) and so far I have had to charge the device only ONCE!!
I must stress that I have no affinity to the manufacturers/marketeers of this device and post this blog entry as a purely independant opinion of a piece of kit that I have personally purchased ( a VERY well spent UK £17.00). I would summarise by saying that, all in all, I find that this is an extremely usable, cool-looking, great piece of bluetooth hardware.