When the device first shipped in 2009, it was with a 4GB SD Card, although if you are looking at adding multiple languages or the other wiki sites you’ll need an 8GB or 16GB card, and if you want to add Project Gutenberg too then it’s definitely a 16GB card that you’ll need. However, whereas before the update was simply a ZIP download, they have now developed their own update software (available in Windows or Max variants) which allows you to choose what you want to download.
This seems to make the device an ever more useful all round tool for reading up about the world; yes, for many of us we have access to all that data online whilst at home and visiting places, but for longer trips, or trips to more remote places (or even just abroad, given the continuation of high data roaming charges on mobile phones), I think the device has a use.
The device is available (for $99) direct from, although I’m hearing they are working to setup a network of country based suppliers, so it’s possible that at some point you’ll be able to order in the UK and avoid customs fees and VAT on the import. Also, when they launched they stated they would offer free updates online, and apart from the ever increasing memory card size requirements, they have live up to that claim, having released two updates during 2010 plus support for all the new wiki sites.