If you’re an Opera Mobile 10 user and if you are like me, then you have spent some time organizing your frequently visited websites into Bookmarks all nice and clean.

To be able to save those Bookmarks so that you no longer have to add and configure them after a Hard Reset or a ROM update, you only have to back up one file, which, starting from Opera Mobile 10 is called “all.dat”. The full path for that is either “Program FilesOpera Mobile 10profiledatastorage2all.dat” or “Windowsprofiledatastorage2all.dat”. Keep that in a safe place (even on your SD Card) and just copy it back if you’ve lost your Bookmarks.

(Source: XDA Developers)