It's different to the Logitech in other ways, too, using a fold-down kickstand to prop up an iPad instead of a canal - a process perfected by using the iPad's magnets once again - and though it has an aluminium outer to match an iPad, the keyboard is white. It's destined to last for over two months between charges.
5. MobileFun Flexible Bluetooth Mini Keyboard - £30/US$48/AU$40
Though not exactly executive-grade, this roll-up keyboard is something of a traveller's gem. Best thought of as an occasional weapon for backpackers - perhaps for emailing sessions or keeping a travel journal - this is super-lightweight gear at a mere 95g (3.35oz), and it rolls up to the size of a Coke can.
Working only with Apple products despite being purely Bluetooth-fuelled, this roll-up is a fully featured keyboard with everything from caps lock and F numbers to fast forward and print screen (a little hopeful, that one). The buttons are a millimetre or so too small, but mistypes - while common - are acceptable, primarily since typing fast is possible, and there are cursor keys and a backspace key to make editing easy. It comes with a retractable mini USB cable for charging, though it lasts for weeks.
6. Logitech Solar Keyboard Folio for iPad - £120/US$130/AU$150
It uses a magnet to instantly switch an iPad on and off when the folio is opened, and can act as an iPad stand in two different positions; the first uses a groove above the keyboard for work, and the second, more laid-back position uses grooves either side of the space bar for movies.
It's expensive, and there are better keyboards available, but if you're after an occasional keyboard and a clean experience, this could be ideal; the solar power makes this the only Bluetooth keyboard around that doesn't need to travel with a micro USB cable in tow for occasional recharging.