Well, other than browsing the internet when at my workplace (hospital), I write letters and memos using abiword (and by converting to pdf I can send them as fax, too). I have lots of reference info in pdf inside; I can also compose new pdf docs by selecting pages of existing pdf's and annotate them in xournal, then close the round trip again, to pdf, again for printing or faxing. Xournal is good also for taking notes in meetings - I am always loosing my paper-based notes and keeping them into the tablet prevents this at all. Sporadicly, I have used spreadsheets on Gnumeric to keep track of numbers and type of patients, but I am not the bean-counter type of guy. Well, and when possible I listen to my music that's there as mp3.
The only way I think I could loosen my workplace security is when logging to its internet connecrion via a portable wifi router, right? But other than encrypting that connection, what would be needed from my part?