Is there a way in Ubuntu (11.10 to be specific) to know which files I open most frequently? That is, which files have been opened the most since installing Ubuntu?
I am unsure what to tag this!
Yes. Ubuntu uses something called Zeitgeist. This is a hierarchical tag system that logs, not only what files you use, but also in which applications you use those files, how you open them, etc. Very cool stuff.
There are several applications you can use to access this data. You can find it in Ubuntu Software Center by following this link: http://apt.ubuntu.com/p/gnome-activity-journal