I live in Norway so I have my iPad 2 language set to Norwegian.
Most of the books I read in iBooks are english. The dictionary is English which is great, however I often try to look up words that are not part of the dictionary. I am then provided with a "search on Wikipedia" option.
Unfortunately this option uses no.wikipedia.org (Norwegian Wikipedia). I wonder if there is a way to change which Wikipedia version iBooks uses? (Without changing the language of the device.)
Best Answer
Yes there is, although you have to modify the iPad's files, so you either have to jailbreak your iPad, then use an app called iFile (paid with a free trial) or openSSH (free but more complicated - I used iFile), or find some way to modify your files without a jailbreak.
An explanation
iOS apps store data on "property list" files. To localise an app they have a property list file that stores all the stuff in the app that they want to change, and what to change it to. The one we are interested in has a field dealing with the Wikipidea search URL, all we have to do is change that URL to go to the English Wikipidea instead of the Norwegian one.
Steps (note that I am using iFile)
Now to test it go to iBooks. When you search Wikipidia it will show the English version. I tested this on my iPod (yes, I put my iPod into Norwegian!) and it worked, so if you have a problem and want me to post pictures for the steps then just leave a comment!