I'll throw my own interpretation of Fi/Fe into the mix too...
Just thought of this analogy: You believe very strongly in fair labor practices around the world. You are diligent about thinking about the ethics behind every purchase you make, because you believe that the best way to influence trends as a consumer is to put your 'money where your mouth is.' You buy fair trade coffee and domestic whenever you can. This is something very important to your core values.
At Christmas time, you've need a new Gadget for school. Gadget A, which is the most popular/best Gadget for your needs, is made in a factory in China, which was recently criticized in the media over its questionable labor practices. Now, you would never buy this Gadget for yourself, but a family member or close friend buys it for you as a Christmas gift. How do you react?
Fe: You graciously accept the gift. Even if it goes against your personal moral standards, you accept these are your own personal standards, not everyone else's. Moreover, it is a well-meaning gesture, and the person put a lot of thought into giving it to you, and you don't want to offend them.
Fi: You thank the giver, but explain that you'll be returning it for another Gadget manufactured under more fair labor practices. You let the person know they shouldn't be offended, because they didn't know, but this is something you personally feel very strongly about, so you cannot live with yourself if you accept this gift.
I'm new to this whole cognitive functions world, so I am open to criticism/reworking.