Sock....
First......I have compasses that are EDC. Multiple in fact.....largest one....mil spec/engineer style.
Second....The kit I put it in has no room for anything but this little magnet.....
Third.....The first thought I had (a quick one) was that it could be used for comapss making.
Fourth.....I use it for other things as well......this little magnet is quite strong....unfortunately there is no place to tie into to allow it to do any retrieving......it does hold several sheets of paper on the side of a vehicle quite well, even in a brisk breeze....Not to mention providing entertainment for both of my boys........keeping them busy 'making a compass' (in and of itself) is worth keeping it in the it....
Fifth......this was more of just an example to get people thinking........

BTW to every one else....thanks....I came away with several great ideas......